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authorAlex Gorrod <alexg@wiredtiger.com>2014-06-13 15:24:01 +1000
committerAlex Gorrod <alexg@wiredtiger.com>2014-06-13 15:24:01 +1000
commit789b3ae862818f8a036072c21b7e557483fb271e (patch)
treeae16df935876f0168ecfa75b6a2ea59ca1ef9c46 /api
parent6a3b23796008effbbb28a9ec9b1939a097273508 (diff)
downloadmongo-789b3ae862818f8a036072c21b7e557483fb271e.tar.gz
Add in the a copy of the LevelDB header files, and use them in our LevelDB API.
This avoids us needing to maintain compatability with the numerous different versions of LevelDB in the wild. Header files will be installed to $include/wiredtiger/leveldb
Diffstat (limited to 'api')
-rw-r--r--api/leveldb/Makefile.am20
-rw-r--r--api/leveldb/include/c.h290
-rw-r--r--api/leveldb/include/cache.h99
-rw-r--r--api/leveldb/include/comparator.h63
-rw-r--r--api/leveldb/include/db.h161
-rw-r--r--api/leveldb/include/env.h333
-rw-r--r--api/leveldb/include/filter_policy.h70
-rw-r--r--api/leveldb/include/iterator.h100
-rw-r--r--api/leveldb/include/options.h195
-rw-r--r--api/leveldb/include/slice.h109
-rw-r--r--api/leveldb/include/status.h106
-rw-r--r--api/leveldb/include/table.h85
-rw-r--r--api/leveldb/include/table_builder.h92
-rw-r--r--api/leveldb/include/write_batch.h64
-rw-r--r--api/leveldb/leveldb_wt.h20
15 files changed, 1796 insertions, 11 deletions
diff --git a/api/leveldb/Makefile.am b/api/leveldb/Makefile.am
index 740dfb16456..555a443da09 100644
--- a/api/leveldb/Makefile.am
+++ b/api/leveldb/Makefile.am
@@ -1,10 +1,28 @@
-AM_CPPFLAGS = -I$(top_builddir)
+AM_CPPFLAGS = -I$(top_builddir) -I$(top_srcdir)/api/leveldb/include
lib_LTLIBRARIES = libwiredtiger_leveldb.la
LDADD = $(lib_LTLIBRARIES) $(top_builddir)/libwiredtiger.la
noinst_PROGRAMS = leveldb_test
+# Setup the LevelDB headers to be installed in a wiredtiger/leveldb
+# subdirectory, so we don't interfere with other LevelDB installs.
+leveldbincludedir = $(includedir)/wiredtiger/leveldb
+leveldbinclude_HEADERS = \
+ include/cache.h \
+ include/c.h \
+ include/comparator.h\
+ include/db.h \
+ include/env.h \
+ include/filter_policy.h \
+ include/iterator.h \
+ include/options.h \
+ include/slice.h \
+ include/status.h \
+ include/table_builder.h \
+ include/table.h \
+ include/write_batch.h
+
libwiredtiger_leveldb_la_LDFLAGS = -release @VERSION@
libwiredtiger_leveldb_la_SOURCES = \
leveldb_wt.cc \
diff --git a/api/leveldb/include/c.h b/api/leveldb/include/c.h
new file mode 100644
index 00000000000..1048fe3b868
--- /dev/null
+++ b/api/leveldb/include/c.h
@@ -0,0 +1,290 @@
+/* Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+ Use of this source code is governed by a BSD-style license that can be
+ found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+ C bindings for leveldb. May be useful as a stable ABI that can be
+ used by programs that keep leveldb in a shared library, or for
+ a JNI api.
+
+ Does not support:
+ . getters for the option types
+ . custom comparators that implement key shortening
+ . custom iter, db, env, cache implementations using just the C bindings
+
+ Some conventions:
+
+ (1) We expose just opaque struct pointers and functions to clients.
+ This allows us to change internal representations without having to
+ recompile clients.
+
+ (2) For simplicity, there is no equivalent to the Slice type. Instead,
+ the caller has to pass the pointer and length as separate
+ arguments.
+
+ (3) Errors are represented by a null-terminated c string. NULL
+ means no error. All operations that can raise an error are passed
+ a "char** errptr" as the last argument. One of the following must
+ be true on entry:
+ *errptr == NULL
+ *errptr points to a malloc()ed null-terminated error message
+ (On Windows, *errptr must have been malloc()-ed by this library.)
+ On success, a leveldb routine leaves *errptr unchanged.
+ On failure, leveldb frees the old value of *errptr and
+ set *errptr to a malloc()ed error message.
+
+ (4) Bools have the type unsigned char (0 == false; rest == true)
+
+ (5) All of the pointer arguments must be non-NULL.
+*/
+
+#ifndef STORAGE_LEVELDB_INCLUDE_C_H_
+#define STORAGE_LEVELDB_INCLUDE_C_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+
+/* Exported types */
+
+typedef struct leveldb_t leveldb_t;
+typedef struct leveldb_cache_t leveldb_cache_t;
+typedef struct leveldb_comparator_t leveldb_comparator_t;
+typedef struct leveldb_env_t leveldb_env_t;
+typedef struct leveldb_filelock_t leveldb_filelock_t;
+typedef struct leveldb_filterpolicy_t leveldb_filterpolicy_t;
+typedef struct leveldb_iterator_t leveldb_iterator_t;
+typedef struct leveldb_logger_t leveldb_logger_t;
+typedef struct leveldb_options_t leveldb_options_t;
+typedef struct leveldb_randomfile_t leveldb_randomfile_t;
+typedef struct leveldb_readoptions_t leveldb_readoptions_t;
+typedef struct leveldb_seqfile_t leveldb_seqfile_t;
+typedef struct leveldb_snapshot_t leveldb_snapshot_t;
+typedef struct leveldb_writablefile_t leveldb_writablefile_t;
+typedef struct leveldb_writebatch_t leveldb_writebatch_t;
+typedef struct leveldb_writeoptions_t leveldb_writeoptions_t;
+
+/* DB operations */
+
+extern leveldb_t* leveldb_open(
+ const leveldb_options_t* options,
+ const char* name,
+ char** errptr);
+
+extern void leveldb_close(leveldb_t* db);
+
+extern void leveldb_put(
+ leveldb_t* db,
+ const leveldb_writeoptions_t* options,
+ const char* key, size_t keylen,
+ const char* val, size_t vallen,
+ char** errptr);
+
+extern void leveldb_delete(
+ leveldb_t* db,
+ const leveldb_writeoptions_t* options,
+ const char* key, size_t keylen,
+ char** errptr);
+
+extern void leveldb_write(
+ leveldb_t* db,
+ const leveldb_writeoptions_t* options,
+ leveldb_writebatch_t* batch,
+ char** errptr);
+
+/* Returns NULL if not found. A malloc()ed array otherwise.
+ Stores the length of the array in *vallen. */
+extern char* leveldb_get(
+ leveldb_t* db,
+ const leveldb_readoptions_t* options,
+ const char* key, size_t keylen,
+ size_t* vallen,
+ char** errptr);
+
+extern leveldb_iterator_t* leveldb_create_iterator(
+ leveldb_t* db,
+ const leveldb_readoptions_t* options);
+
+extern const leveldb_snapshot_t* leveldb_create_snapshot(
+ leveldb_t* db);
+
+extern void leveldb_release_snapshot(
+ leveldb_t* db,
+ const leveldb_snapshot_t* snapshot);
+
+/* Returns NULL if property name is unknown.
+ Else returns a pointer to a malloc()-ed null-terminated value. */
+extern char* leveldb_property_value(
+ leveldb_t* db,
+ const char* propname);
+
+extern void leveldb_approximate_sizes(
+ leveldb_t* db,
+ int num_ranges,
+ const char* const* range_start_key, const size_t* range_start_key_len,
+ const char* const* range_limit_key, const size_t* range_limit_key_len,
+ uint64_t* sizes);
+
+extern void leveldb_compact_range(
+ leveldb_t* db,
+ const char* start_key, size_t start_key_len,
+ const char* limit_key, size_t limit_key_len);
+
+/* Management operations */
+
+extern void leveldb_destroy_db(
+ const leveldb_options_t* options,
+ const char* name,
+ char** errptr);
+
+extern void leveldb_repair_db(
+ const leveldb_options_t* options,
+ const char* name,
+ char** errptr);
+
+/* Iterator */
+
+extern void leveldb_iter_destroy(leveldb_iterator_t*);
+extern unsigned char leveldb_iter_valid(const leveldb_iterator_t*);
+extern void leveldb_iter_seek_to_first(leveldb_iterator_t*);
+extern void leveldb_iter_seek_to_last(leveldb_iterator_t*);
+extern void leveldb_iter_seek(leveldb_iterator_t*, const char* k, size_t klen);
+extern void leveldb_iter_next(leveldb_iterator_t*);
+extern void leveldb_iter_prev(leveldb_iterator_t*);
+extern const char* leveldb_iter_key(const leveldb_iterator_t*, size_t* klen);
+extern const char* leveldb_iter_value(const leveldb_iterator_t*, size_t* vlen);
+extern void leveldb_iter_get_error(const leveldb_iterator_t*, char** errptr);
+
+/* Write batch */
+
+extern leveldb_writebatch_t* leveldb_writebatch_create();
+extern void leveldb_writebatch_destroy(leveldb_writebatch_t*);
+extern void leveldb_writebatch_clear(leveldb_writebatch_t*);
+extern void leveldb_writebatch_put(
+ leveldb_writebatch_t*,
+ const char* key, size_t klen,
+ const char* val, size_t vlen);
+extern void leveldb_writebatch_delete(
+ leveldb_writebatch_t*,
+ const char* key, size_t klen);
+extern void leveldb_writebatch_iterate(
+ leveldb_writebatch_t*,
+ void* state,
+ void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
+ void (*deleted)(void*, const char* k, size_t klen));
+
+/* Options */
+
+extern leveldb_options_t* leveldb_options_create();
+extern void leveldb_options_destroy(leveldb_options_t*);
+extern void leveldb_options_set_comparator(
+ leveldb_options_t*,
+ leveldb_comparator_t*);
+extern void leveldb_options_set_filter_policy(
+ leveldb_options_t*,
+ leveldb_filterpolicy_t*);
+extern void leveldb_options_set_create_if_missing(
+ leveldb_options_t*, unsigned char);
+extern void leveldb_options_set_error_if_exists(
+ leveldb_options_t*, unsigned char);
+extern void leveldb_options_set_paranoid_checks(
+ leveldb_options_t*, unsigned char);
+extern void leveldb_options_set_env(leveldb_options_t*, leveldb_env_t*);
+extern void leveldb_options_set_info_log(leveldb_options_t*, leveldb_logger_t*);
+extern void leveldb_options_set_write_buffer_size(leveldb_options_t*, size_t);
+extern void leveldb_options_set_max_open_files(leveldb_options_t*, int);
+extern void leveldb_options_set_cache(leveldb_options_t*, leveldb_cache_t*);
+extern void leveldb_options_set_block_size(leveldb_options_t*, size_t);
+extern void leveldb_options_set_block_restart_interval(leveldb_options_t*, int);
+
+enum {
+ leveldb_no_compression = 0,
+ leveldb_snappy_compression = 1
+};
+extern void leveldb_options_set_compression(leveldb_options_t*, int);
+
+/* Comparator */
+
+extern leveldb_comparator_t* leveldb_comparator_create(
+ void* state,
+ void (*destructor)(void*),
+ int (*compare)(
+ void*,
+ const char* a, size_t alen,
+ const char* b, size_t blen),
+ const char* (*name)(void*));
+extern void leveldb_comparator_destroy(leveldb_comparator_t*);
+
+/* Filter policy */
+
+extern leveldb_filterpolicy_t* leveldb_filterpolicy_create(
+ void* state,
+ void (*destructor)(void*),
+ char* (*create_filter)(
+ void*,
+ const char* const* key_array, const size_t* key_length_array,
+ int num_keys,
+ size_t* filter_length),
+ unsigned char (*key_may_match)(
+ void*,
+ const char* key, size_t length,
+ const char* filter, size_t filter_length),
+ const char* (*name)(void*));
+extern void leveldb_filterpolicy_destroy(leveldb_filterpolicy_t*);
+
+extern leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(
+ int bits_per_key);
+
+/* Read options */
+
+extern leveldb_readoptions_t* leveldb_readoptions_create();
+extern void leveldb_readoptions_destroy(leveldb_readoptions_t*);
+extern void leveldb_readoptions_set_verify_checksums(
+ leveldb_readoptions_t*,
+ unsigned char);
+extern void leveldb_readoptions_set_fill_cache(
+ leveldb_readoptions_t*, unsigned char);
+extern void leveldb_readoptions_set_snapshot(
+ leveldb_readoptions_t*,
+ const leveldb_snapshot_t*);
+
+/* Write options */
+
+extern leveldb_writeoptions_t* leveldb_writeoptions_create();
+extern void leveldb_writeoptions_destroy(leveldb_writeoptions_t*);
+extern void leveldb_writeoptions_set_sync(
+ leveldb_writeoptions_t*, unsigned char);
+
+/* Cache */
+
+extern leveldb_cache_t* leveldb_cache_create_lru(size_t capacity);
+extern void leveldb_cache_destroy(leveldb_cache_t* cache);
+
+/* Env */
+
+extern leveldb_env_t* leveldb_create_default_env();
+extern void leveldb_env_destroy(leveldb_env_t*);
+
+/* Utility */
+
+/* Calls free(ptr).
+ REQUIRES: ptr was malloc()-ed and returned by one of the routines
+ in this file. Note that in certain cases (typically on Windows), you
+ may need to call this routine instead of free(ptr) to dispose of
+ malloc()-ed memory returned by this library. */
+extern void leveldb_free(void* ptr);
+
+/* Return the major version number for this release. */
+extern int leveldb_major_version();
+
+/* Return the minor version number for this release. */
+extern int leveldb_minor_version();
+
+#ifdef __cplusplus
+} /* end extern "C" */
+#endif
+
+#endif /* STORAGE_LEVELDB_INCLUDE_C_H_ */
diff --git a/api/leveldb/include/cache.h b/api/leveldb/include/cache.h
new file mode 100644
index 00000000000..5e3b47637d4
--- /dev/null
+++ b/api/leveldb/include/cache.h
@@ -0,0 +1,99 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// A Cache is an interface that maps keys to values. It has internal
+// synchronization and may be safely accessed concurrently from
+// multiple threads. It may automatically evict entries to make room
+// for new entries. Values have a specified charge against the cache
+// capacity. For example, a cache where the values are variable
+// length strings, may use the length of the string as the charge for
+// the string.
+//
+// A builtin cache implementation with a least-recently-used eviction
+// policy is provided. Clients may use their own implementations if
+// they want something more sophisticated (like scan-resistance, a
+// custom eviction policy, variable cache sizing, etc.)
+
+#ifndef STORAGE_LEVELDB_INCLUDE_CACHE_H_
+#define STORAGE_LEVELDB_INCLUDE_CACHE_H_
+
+#include <stdint.h>
+#include "leveldb/slice.h"
+
+namespace leveldb {
+
+class Cache;
+
+// Create a new cache with a fixed size capacity. This implementation
+// of Cache uses a least-recently-used eviction policy.
+extern Cache* NewLRUCache(size_t capacity);
+
+class Cache {
+ public:
+ Cache() { }
+
+ // Destroys all existing entries by calling the "deleter"
+ // function that was passed to the constructor.
+ virtual ~Cache();
+
+ // Opaque handle to an entry stored in the cache.
+ struct Handle { };
+
+ // Insert a mapping from key->value into the cache and assign it
+ // the specified charge against the total cache capacity.
+ //
+ // Returns a handle that corresponds to the mapping. The caller
+ // must call this->Release(handle) when the returned mapping is no
+ // longer needed.
+ //
+ // When the inserted entry is no longer needed, the key and
+ // value will be passed to "deleter".
+ virtual Handle* Insert(const Slice& key, void* value, size_t charge,
+ void (*deleter)(const Slice& key, void* value)) = 0;
+
+ // If the cache has no mapping for "key", returns NULL.
+ //
+ // Else return a handle that corresponds to the mapping. The caller
+ // must call this->Release(handle) when the returned mapping is no
+ // longer needed.
+ virtual Handle* Lookup(const Slice& key) = 0;
+
+ // Release a mapping returned by a previous Lookup().
+ // REQUIRES: handle must not have been released yet.
+ // REQUIRES: handle must have been returned by a method on *this.
+ virtual void Release(Handle* handle) = 0;
+
+ // Return the value encapsulated in a handle returned by a
+ // successful Lookup().
+ // REQUIRES: handle must not have been released yet.
+ // REQUIRES: handle must have been returned by a method on *this.
+ virtual void* Value(Handle* handle) = 0;
+
+ // If the cache contains entry for key, erase it. Note that the
+ // underlying entry will be kept around until all existing handles
+ // to it have been released.
+ virtual void Erase(const Slice& key) = 0;
+
+ // Return a new numeric id. May be used by multiple clients who are
+ // sharing the same cache to partition the key space. Typically the
+ // client will allocate a new id at startup and prepend the id to
+ // its cache keys.
+ virtual uint64_t NewId() = 0;
+
+ private:
+ void LRU_Remove(Handle* e);
+ void LRU_Append(Handle* e);
+ void Unref(Handle* e);
+
+ struct Rep;
+ Rep* rep_;
+
+ // No copying allowed
+ Cache(const Cache&);
+ void operator=(const Cache&);
+};
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_UTIL_CACHE_H_
diff --git a/api/leveldb/include/comparator.h b/api/leveldb/include/comparator.h
new file mode 100644
index 00000000000..556b984c769
--- /dev/null
+++ b/api/leveldb/include/comparator.h
@@ -0,0 +1,63 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_COMPARATOR_H_
+#define STORAGE_LEVELDB_INCLUDE_COMPARATOR_H_
+
+#include <string>
+
+namespace leveldb {
+
+class Slice;
+
+// A Comparator object provides a total order across slices that are
+// used as keys in an sstable or a database. A Comparator implementation
+// must be thread-safe since leveldb may invoke its methods concurrently
+// from multiple threads.
+class Comparator {
+ public:
+ virtual ~Comparator();
+
+ // Three-way comparison. Returns value:
+ // < 0 iff "a" < "b",
+ // == 0 iff "a" == "b",
+ // > 0 iff "a" > "b"
+ virtual int Compare(const Slice& a, const Slice& b) const = 0;
+
+ // The name of the comparator. Used to check for comparator
+ // mismatches (i.e., a DB created with one comparator is
+ // accessed using a different comparator.
+ //
+ // The client of this package should switch to a new name whenever
+ // the comparator implementation changes in a way that will cause
+ // the relative ordering of any two keys to change.
+ //
+ // Names starting with "leveldb." are reserved and should not be used
+ // by any clients of this package.
+ virtual const char* Name() const = 0;
+
+ // Advanced functions: these are used to reduce the space requirements
+ // for internal data structures like index blocks.
+
+ // If *start < limit, changes *start to a short string in [start,limit).
+ // Simple comparator implementations may return with *start unchanged,
+ // i.e., an implementation of this method that does nothing is correct.
+ virtual void FindShortestSeparator(
+ std::string* start,
+ const Slice& limit) const = 0;
+
+ // Changes *key to a short string >= *key.
+ // Simple comparator implementations may return with *key unchanged,
+ // i.e., an implementation of this method that does nothing is correct.
+ virtual void FindShortSuccessor(std::string* key) const = 0;
+};
+
+// Return a builtin comparator that uses lexicographic byte-wise
+// ordering. The result remains the property of this module and
+// must not be deleted.
+extern const Comparator* BytewiseComparator();
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_COMPARATOR_H_
diff --git a/api/leveldb/include/db.h b/api/leveldb/include/db.h
new file mode 100644
index 00000000000..40851b2aa83
--- /dev/null
+++ b/api/leveldb/include/db.h
@@ -0,0 +1,161 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_DB_H_
+#define STORAGE_LEVELDB_INCLUDE_DB_H_
+
+#include <stdint.h>
+#include <stdio.h>
+#include "leveldb/iterator.h"
+#include "leveldb/options.h"
+
+namespace leveldb {
+
+// Update Makefile if you change these
+static const int kMajorVersion = 1;
+static const int kMinorVersion = 17;
+
+struct Options;
+struct ReadOptions;
+struct WriteOptions;
+class WriteBatch;
+
+// Abstract handle to particular state of a DB.
+// A Snapshot is an immutable object and can therefore be safely
+// accessed from multiple threads without any external synchronization.
+class Snapshot {
+ protected:
+ virtual ~Snapshot();
+};
+
+// A range of keys
+struct Range {
+ Slice start; // Included in the range
+ Slice limit; // Not included in the range
+
+ Range() { }
+ Range(const Slice& s, const Slice& l) : start(s), limit(l) { }
+};
+
+// A DB is a persistent ordered map from keys to values.
+// A DB is safe for concurrent access from multiple threads without
+// any external synchronization.
+class DB {
+ public:
+ // Open the database with the specified "name".
+ // Stores a pointer to a heap-allocated database in *dbptr and returns
+ // OK on success.
+ // Stores NULL in *dbptr and returns a non-OK status on error.
+ // Caller should delete *dbptr when it is no longer needed.
+ static Status Open(const Options& options,
+ const std::string& name,
+ DB** dbptr);
+
+ DB() { }
+ virtual ~DB();
+
+ // Set the database entry for "key" to "value". Returns OK on success,
+ // and a non-OK status on error.
+ // Note: consider setting options.sync = true.
+ virtual Status Put(const WriteOptions& options,
+ const Slice& key,
+ const Slice& value) = 0;
+
+ // Remove the database entry (if any) for "key". Returns OK on
+ // success, and a non-OK status on error. It is not an error if "key"
+ // did not exist in the database.
+ // Note: consider setting options.sync = true.
+ virtual Status Delete(const WriteOptions& options, const Slice& key) = 0;
+
+ // Apply the specified updates to the database.
+ // Returns OK on success, non-OK on failure.
+ // Note: consider setting options.sync = true.
+ virtual Status Write(const WriteOptions& options, WriteBatch* updates) = 0;
+
+ // If the database contains an entry for "key" store the
+ // corresponding value in *value and return OK.
+ //
+ // If there is no entry for "key" leave *value unchanged and return
+ // a status for which Status::IsNotFound() returns true.
+ //
+ // May return some other Status on an error.
+ virtual Status Get(const ReadOptions& options,
+ const Slice& key, std::string* value) = 0;
+
+ // Return a heap-allocated iterator over the contents of the database.
+ // The result of NewIterator() is initially invalid (caller must
+ // call one of the Seek methods on the iterator before using it).
+ //
+ // Caller should delete the iterator when it is no longer needed.
+ // The returned iterator should be deleted before this db is deleted.
+ virtual Iterator* NewIterator(const ReadOptions& options) = 0;
+
+ // Return a handle to the current DB state. Iterators created with
+ // this handle will all observe a stable snapshot of the current DB
+ // state. The caller must call ReleaseSnapshot(result) when the
+ // snapshot is no longer needed.
+ virtual const Snapshot* GetSnapshot() = 0;
+
+ // Release a previously acquired snapshot. The caller must not
+ // use "snapshot" after this call.
+ virtual void ReleaseSnapshot(const Snapshot* snapshot) = 0;
+
+ // DB implementations can export properties about their state
+ // via this method. If "property" is a valid property understood by this
+ // DB implementation, fills "*value" with its current value and returns
+ // true. Otherwise returns false.
+ //
+ //
+ // Valid property names include:
+ //
+ // "leveldb.num-files-at-level<N>" - return the number of files at level <N>,
+ // where <N> is an ASCII representation of a level number (e.g. "0").
+ // "leveldb.stats" - returns a multi-line string that describes statistics
+ // about the internal operation of the DB.
+ // "leveldb.sstables" - returns a multi-line string that describes all
+ // of the sstables that make up the db contents.
+ virtual bool GetProperty(const Slice& property, std::string* value) = 0;
+
+ // For each i in [0,n-1], store in "sizes[i]", the approximate
+ // file system space used by keys in "[range[i].start .. range[i].limit)".
+ //
+ // Note that the returned sizes measure file system space usage, so
+ // if the user data compresses by a factor of ten, the returned
+ // sizes will be one-tenth the size of the corresponding user data size.
+ //
+ // The results may not include the sizes of recently written data.
+ virtual void GetApproximateSizes(const Range* range, int n,
+ uint64_t* sizes) = 0;
+
+ // Compact the underlying storage for the key range [*begin,*end].
+ // In particular, deleted and overwritten versions are discarded,
+ // and the data is rearranged to reduce the cost of operations
+ // needed to access the data. This operation should typically only
+ // be invoked by users who understand the underlying implementation.
+ //
+ // begin==NULL is treated as a key before all keys in the database.
+ // end==NULL is treated as a key after all keys in the database.
+ // Therefore the following call will compact the entire database:
+ // db->CompactRange(NULL, NULL);
+ virtual void CompactRange(const Slice* begin, const Slice* end) = 0;
+
+ private:
+ // No copying allowed
+ DB(const DB&);
+ void operator=(const DB&);
+};
+
+// Destroy the contents of the specified database.
+// Be very careful using this method.
+Status DestroyDB(const std::string& name, const Options& options);
+
+// If a DB cannot be opened, you may attempt to call this method to
+// resurrect as much of the contents of the database as possible.
+// Some data may be lost, so be careful when calling this function
+// on a database that contains important information.
+Status RepairDB(const std::string& dbname, const Options& options);
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_DB_H_
diff --git a/api/leveldb/include/env.h b/api/leveldb/include/env.h
new file mode 100644
index 00000000000..b2072d02c1c
--- /dev/null
+++ b/api/leveldb/include/env.h
@@ -0,0 +1,333 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// An Env is an interface used by the leveldb implementation to access
+// operating system functionality like the filesystem etc. Callers
+// may wish to provide a custom Env object when opening a database to
+// get fine gain control; e.g., to rate limit file system operations.
+//
+// All Env implementations are safe for concurrent access from
+// multiple threads without any external synchronization.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_ENV_H_
+#define STORAGE_LEVELDB_INCLUDE_ENV_H_
+
+#include <string>
+#include <vector>
+#include <stdarg.h>
+#include <stdint.h>
+#include "leveldb/status.h"
+
+namespace leveldb {
+
+class FileLock;
+class Logger;
+class RandomAccessFile;
+class SequentialFile;
+class Slice;
+class WritableFile;
+
+class Env {
+ public:
+ Env() { }
+ virtual ~Env();
+
+ // Return a default environment suitable for the current operating
+ // system. Sophisticated users may wish to provide their own Env
+ // implementation instead of relying on this default environment.
+ //
+ // The result of Default() belongs to leveldb and must never be deleted.
+ static Env* Default();
+
+ // Create a brand new sequentially-readable file with the specified name.
+ // On success, stores a pointer to the new file in *result and returns OK.
+ // On failure stores NULL in *result and returns non-OK. If the file does
+ // not exist, returns a non-OK status.
+ //
+ // The returned file will only be accessed by one thread at a time.
+ virtual Status NewSequentialFile(const std::string& fname,
+ SequentialFile** result) = 0;
+
+ // Create a brand new random access read-only file with the
+ // specified name. On success, stores a pointer to the new file in
+ // *result and returns OK. On failure stores NULL in *result and
+ // returns non-OK. If the file does not exist, returns a non-OK
+ // status.
+ //
+ // The returned file may be concurrently accessed by multiple threads.
+ virtual Status NewRandomAccessFile(const std::string& fname,
+ RandomAccessFile** result) = 0;
+
+ // Create an object that writes to a new file with the specified
+ // name. Deletes any existing file with the same name and creates a
+ // new file. On success, stores a pointer to the new file in
+ // *result and returns OK. On failure stores NULL in *result and
+ // returns non-OK.
+ //
+ // The returned file will only be accessed by one thread at a time.
+ virtual Status NewWritableFile(const std::string& fname,
+ WritableFile** result) = 0;
+
+ // Returns true iff the named file exists.
+ virtual bool FileExists(const std::string& fname) = 0;
+
+ // Store in *result the names of the children of the specified directory.
+ // The names are relative to "dir".
+ // Original contents of *results are dropped.
+ virtual Status GetChildren(const std::string& dir,
+ std::vector<std::string>* result) = 0;
+
+ // Delete the named file.
+ virtual Status DeleteFile(const std::string& fname) = 0;
+
+ // Create the specified directory.
+ virtual Status CreateDir(const std::string& dirname) = 0;
+
+ // Delete the specified directory.
+ virtual Status DeleteDir(const std::string& dirname) = 0;
+
+ // Store the size of fname in *file_size.
+ virtual Status GetFileSize(const std::string& fname, uint64_t* file_size) = 0;
+
+ // Rename file src to target.
+ virtual Status RenameFile(const std::string& src,
+ const std::string& target) = 0;
+
+ // Lock the specified file. Used to prevent concurrent access to
+ // the same db by multiple processes. On failure, stores NULL in
+ // *lock and returns non-OK.
+ //
+ // On success, stores a pointer to the object that represents the
+ // acquired lock in *lock and returns OK. The caller should call
+ // UnlockFile(*lock) to release the lock. If the process exits,
+ // the lock will be automatically released.
+ //
+ // If somebody else already holds the lock, finishes immediately
+ // with a failure. I.e., this call does not wait for existing locks
+ // to go away.
+ //
+ // May create the named file if it does not already exist.
+ virtual Status LockFile(const std::string& fname, FileLock** lock) = 0;
+
+ // Release the lock acquired by a previous successful call to LockFile.
+ // REQUIRES: lock was returned by a successful LockFile() call
+ // REQUIRES: lock has not already been unlocked.
+ virtual Status UnlockFile(FileLock* lock) = 0;
+
+ // Arrange to run "(*function)(arg)" once in a background thread.
+ //
+ // "function" may run in an unspecified thread. Multiple functions
+ // added to the same Env may run concurrently in different threads.
+ // I.e., the caller may not assume that background work items are
+ // serialized.
+ virtual void Schedule(
+ void (*function)(void* arg),
+ void* arg) = 0;
+
+ // Start a new thread, invoking "function(arg)" within the new thread.
+ // When "function(arg)" returns, the thread will be destroyed.
+ virtual void StartThread(void (*function)(void* arg), void* arg) = 0;
+
+ // *path is set to a temporary directory that can be used for testing. It may
+ // or many not have just been created. The directory may or may not differ
+ // between runs of the same process, but subsequent calls will return the
+ // same directory.
+ virtual Status GetTestDirectory(std::string* path) = 0;
+
+ // Create and return a log file for storing informational messages.
+ virtual Status NewLogger(const std::string& fname, Logger** result) = 0;
+
+ // Returns the number of micro-seconds since some fixed point in time. Only
+ // useful for computing deltas of time.
+ virtual uint64_t NowMicros() = 0;
+
+ // Sleep/delay the thread for the perscribed number of micro-seconds.
+ virtual void SleepForMicroseconds(int micros) = 0;
+
+ private:
+ // No copying allowed
+ Env(const Env&);
+ void operator=(const Env&);
+};
+
+// A file abstraction for reading sequentially through a file
+class SequentialFile {
+ public:
+ SequentialFile() { }
+ virtual ~SequentialFile();
+
+ // Read up to "n" bytes from the file. "scratch[0..n-1]" may be
+ // written by this routine. Sets "*result" to the data that was
+ // read (including if fewer than "n" bytes were successfully read).
+ // May set "*result" to point at data in "scratch[0..n-1]", so
+ // "scratch[0..n-1]" must be live when "*result" is used.
+ // If an error was encountered, returns a non-OK status.
+ //
+ // REQUIRES: External synchronization
+ virtual Status Read(size_t n, Slice* result, char* scratch) = 0;
+
+ // Skip "n" bytes from the file. This is guaranteed to be no
+ // slower that reading the same data, but may be faster.
+ //
+ // If end of file is reached, skipping will stop at the end of the
+ // file, and Skip will return OK.
+ //
+ // REQUIRES: External synchronization
+ virtual Status Skip(uint64_t n) = 0;
+
+ private:
+ // No copying allowed
+ SequentialFile(const SequentialFile&);
+ void operator=(const SequentialFile&);
+};
+
+// A file abstraction for randomly reading the contents of a file.
+class RandomAccessFile {
+ public:
+ RandomAccessFile() { }
+ virtual ~RandomAccessFile();
+
+ // Read up to "n" bytes from the file starting at "offset".
+ // "scratch[0..n-1]" may be written by this routine. Sets "*result"
+ // to the data that was read (including if fewer than "n" bytes were
+ // successfully read). May set "*result" to point at data in
+ // "scratch[0..n-1]", so "scratch[0..n-1]" must be live when
+ // "*result" is used. If an error was encountered, returns a non-OK
+ // status.
+ //
+ // Safe for concurrent use by multiple threads.
+ virtual Status Read(uint64_t offset, size_t n, Slice* result,
+ char* scratch) const = 0;
+
+ private:
+ // No copying allowed
+ RandomAccessFile(const RandomAccessFile&);
+ void operator=(const RandomAccessFile&);
+};
+
+// A file abstraction for sequential writing. The implementation
+// must provide buffering since callers may append small fragments
+// at a time to the file.
+class WritableFile {
+ public:
+ WritableFile() { }
+ virtual ~WritableFile();
+
+ virtual Status Append(const Slice& data) = 0;
+ virtual Status Close() = 0;
+ virtual Status Flush() = 0;
+ virtual Status Sync() = 0;
+
+ private:
+ // No copying allowed
+ WritableFile(const WritableFile&);
+ void operator=(const WritableFile&);
+};
+
+// An interface for writing log messages.
+class Logger {
+ public:
+ Logger() { }
+ virtual ~Logger();
+
+ // Write an entry to the log file with the specified format.
+ virtual void Logv(const char* format, va_list ap) = 0;
+
+ private:
+ // No copying allowed
+ Logger(const Logger&);
+ void operator=(const Logger&);
+};
+
+
+// Identifies a locked file.
+class FileLock {
+ public:
+ FileLock() { }
+ virtual ~FileLock();
+ private:
+ // No copying allowed
+ FileLock(const FileLock&);
+ void operator=(const FileLock&);
+};
+
+// Log the specified data to *info_log if info_log is non-NULL.
+extern void Log(Logger* info_log, const char* format, ...)
+# if defined(__GNUC__) || defined(__clang__)
+ __attribute__((__format__ (__printf__, 2, 3)))
+# endif
+ ;
+
+// A utility routine: write "data" to the named file.
+extern Status WriteStringToFile(Env* env, const Slice& data,
+ const std::string& fname);
+
+// A utility routine: read contents of named file into *data
+extern Status ReadFileToString(Env* env, const std::string& fname,
+ std::string* data);
+
+// An implementation of Env that forwards all calls to another Env.
+// May be useful to clients who wish to override just part of the
+// functionality of another Env.
+class EnvWrapper : public Env {
+ public:
+ // Initialize an EnvWrapper that delegates all calls to *t
+ explicit EnvWrapper(Env* t) : target_(t) { }
+ virtual ~EnvWrapper();
+
+ // Return the target to which this Env forwards all calls
+ Env* target() const { return target_; }
+
+ // The following text is boilerplate that forwards all methods to target()
+ Status NewSequentialFile(const std::string& f, SequentialFile** r) {
+ return target_->NewSequentialFile(f, r);
+ }
+ Status NewRandomAccessFile(const std::string& f, RandomAccessFile** r) {
+ return target_->NewRandomAccessFile(f, r);
+ }
+ Status NewWritableFile(const std::string& f, WritableFile** r) {
+ return target_->NewWritableFile(f, r);
+ }
+ bool FileExists(const std::string& f) { return target_->FileExists(f); }
+ Status GetChildren(const std::string& dir, std::vector<std::string>* r) {
+ return target_->GetChildren(dir, r);
+ }
+ Status DeleteFile(const std::string& f) { return target_->DeleteFile(f); }
+ Status CreateDir(const std::string& d) { return target_->CreateDir(d); }
+ Status DeleteDir(const std::string& d) { return target_->DeleteDir(d); }
+ Status GetFileSize(const std::string& f, uint64_t* s) {
+ return target_->GetFileSize(f, s);
+ }
+ Status RenameFile(const std::string& s, const std::string& t) {
+ return target_->RenameFile(s, t);
+ }
+ Status LockFile(const std::string& f, FileLock** l) {
+ return target_->LockFile(f, l);
+ }
+ Status UnlockFile(FileLock* l) { return target_->UnlockFile(l); }
+ void Schedule(void (*f)(void*), void* a) {
+ return target_->Schedule(f, a);
+ }
+ void StartThread(void (*f)(void*), void* a) {
+ return target_->StartThread(f, a);
+ }
+ virtual Status GetTestDirectory(std::string* path) {
+ return target_->GetTestDirectory(path);
+ }
+ virtual Status NewLogger(const std::string& fname, Logger** result) {
+ return target_->NewLogger(fname, result);
+ }
+ uint64_t NowMicros() {
+ return target_->NowMicros();
+ }
+ void SleepForMicroseconds(int micros) {
+ target_->SleepForMicroseconds(micros);
+ }
+ private:
+ Env* target_;
+};
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_ENV_H_
diff --git a/api/leveldb/include/filter_policy.h b/api/leveldb/include/filter_policy.h
new file mode 100644
index 00000000000..1fba08001fc
--- /dev/null
+++ b/api/leveldb/include/filter_policy.h
@@ -0,0 +1,70 @@
+// Copyright (c) 2012 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// A database can be configured with a custom FilterPolicy object.
+// This object is responsible for creating a small filter from a set
+// of keys. These filters are stored in leveldb and are consulted
+// automatically by leveldb to decide whether or not to read some
+// information from disk. In many cases, a filter can cut down the
+// number of disk seeks form a handful to a single disk seek per
+// DB::Get() call.
+//
+// Most people will want to use the builtin bloom filter support (see
+// NewBloomFilterPolicy() below).
+
+#ifndef STORAGE_LEVELDB_INCLUDE_FILTER_POLICY_H_
+#define STORAGE_LEVELDB_INCLUDE_FILTER_POLICY_H_
+
+#include <string>
+
+namespace leveldb {
+
+class Slice;
+
+class FilterPolicy {
+ public:
+ virtual ~FilterPolicy();
+
+ // Return the name of this policy. Note that if the filter encoding
+ // changes in an incompatible way, the name returned by this method
+ // must be changed. Otherwise, old incompatible filters may be
+ // passed to methods of this type.
+ virtual const char* Name() const = 0;
+
+ // keys[0,n-1] contains a list of keys (potentially with duplicates)
+ // that are ordered according to the user supplied comparator.
+ // Append a filter that summarizes keys[0,n-1] to *dst.
+ //
+ // Warning: do not change the initial contents of *dst. Instead,
+ // append the newly constructed filter to *dst.
+ virtual void CreateFilter(const Slice* keys, int n, std::string* dst)
+ const = 0;
+
+ // "filter" contains the data appended by a preceding call to
+ // CreateFilter() on this class. This method must return true if
+ // the key was in the list of keys passed to CreateFilter().
+ // This method may return true or false if the key was not on the
+ // list, but it should aim to return false with a high probability.
+ virtual bool KeyMayMatch(const Slice& key, const Slice& filter) const = 0;
+};
+
+// Return a new filter policy that uses a bloom filter with approximately
+// the specified number of bits per key. A good value for bits_per_key
+// is 10, which yields a filter with ~ 1% false positive rate.
+//
+// Callers must delete the result after any database that is using the
+// result has been closed.
+//
+// Note: if you are using a custom comparator that ignores some parts
+// of the keys being compared, you must not use NewBloomFilterPolicy()
+// and must provide your own FilterPolicy that also ignores the
+// corresponding parts of the keys. For example, if the comparator
+// ignores trailing spaces, it would be incorrect to use a
+// FilterPolicy (like NewBloomFilterPolicy) that does not ignore
+// trailing spaces in keys.
+extern const FilterPolicy* NewBloomFilterPolicy(int bits_per_key);
+
+}
+
+#endif // STORAGE_LEVELDB_INCLUDE_FILTER_POLICY_H_
diff --git a/api/leveldb/include/iterator.h b/api/leveldb/include/iterator.h
new file mode 100644
index 00000000000..ad543eb46cd
--- /dev/null
+++ b/api/leveldb/include/iterator.h
@@ -0,0 +1,100 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// An iterator yields a sequence of key/value pairs from a source.
+// The following class defines the interface. Multiple implementations
+// are provided by this library. In particular, iterators are provided
+// to access the contents of a Table or a DB.
+//
+// Multiple threads can invoke const methods on an Iterator without
+// external synchronization, but if any of the threads may call a
+// non-const method, all threads accessing the same Iterator must use
+// external synchronization.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_ITERATOR_H_
+#define STORAGE_LEVELDB_INCLUDE_ITERATOR_H_
+
+#include "leveldb/slice.h"
+#include "leveldb/status.h"
+
+namespace leveldb {
+
+class Iterator {
+ public:
+ Iterator();
+ virtual ~Iterator();
+
+ // An iterator is either positioned at a key/value pair, or
+ // not valid. This method returns true iff the iterator is valid.
+ virtual bool Valid() const = 0;
+
+ // Position at the first key in the source. The iterator is Valid()
+ // after this call iff the source is not empty.
+ virtual void SeekToFirst() = 0;
+
+ // Position at the last key in the source. The iterator is
+ // Valid() after this call iff the source is not empty.
+ virtual void SeekToLast() = 0;
+
+ // Position at the first key in the source that at or past target
+ // The iterator is Valid() after this call iff the source contains
+ // an entry that comes at or past target.
+ virtual void Seek(const Slice& target) = 0;
+
+ // Moves to the next entry in the source. After this call, Valid() is
+ // true iff the iterator was not positioned at the last entry in the source.
+ // REQUIRES: Valid()
+ virtual void Next() = 0;
+
+ // Moves to the previous entry in the source. After this call, Valid() is
+ // true iff the iterator was not positioned at the first entry in source.
+ // REQUIRES: Valid()
+ virtual void Prev() = 0;
+
+ // Return the key for the current entry. The underlying storage for
+ // the returned slice is valid only until the next modification of
+ // the iterator.
+ // REQUIRES: Valid()
+ virtual Slice key() const = 0;
+
+ // Return the value for the current entry. The underlying storage for
+ // the returned slice is valid only until the next modification of
+ // the iterator.
+ // REQUIRES: !AtEnd() && !AtStart()
+ virtual Slice value() const = 0;
+
+ // If an error has occurred, return it. Else return an ok status.
+ virtual Status status() const = 0;
+
+ // Clients are allowed to register function/arg1/arg2 triples that
+ // will be invoked when this iterator is destroyed.
+ //
+ // Note that unlike all of the preceding methods, this method is
+ // not abstract and therefore clients should not override it.
+ typedef void (*CleanupFunction)(void* arg1, void* arg2);
+ void RegisterCleanup(CleanupFunction function, void* arg1, void* arg2);
+
+ private:
+ struct Cleanup {
+ CleanupFunction function;
+ void* arg1;
+ void* arg2;
+ Cleanup* next;
+ };
+ Cleanup cleanup_;
+
+ // No copying allowed
+ Iterator(const Iterator&);
+ void operator=(const Iterator&);
+};
+
+// Return an empty iterator (yields nothing).
+extern Iterator* NewEmptyIterator();
+
+// Return an empty iterator with the specified status.
+extern Iterator* NewErrorIterator(const Status& status);
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_ITERATOR_H_
diff --git a/api/leveldb/include/options.h b/api/leveldb/include/options.h
new file mode 100644
index 00000000000..fdda718d309
--- /dev/null
+++ b/api/leveldb/include/options.h
@@ -0,0 +1,195 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_OPTIONS_H_
+#define STORAGE_LEVELDB_INCLUDE_OPTIONS_H_
+
+#include <stddef.h>
+
+namespace leveldb {
+
+class Cache;
+class Comparator;
+class Env;
+class FilterPolicy;
+class Logger;
+class Snapshot;
+
+// DB contents are stored in a set of blocks, each of which holds a
+// sequence of key,value pairs. Each block may be compressed before
+// being stored in a file. The following enum describes which
+// compression method (if any) is used to compress a block.
+enum CompressionType {
+ // NOTE: do not change the values of existing entries, as these are
+ // part of the persistent format on disk.
+ kNoCompression = 0x0,
+ kSnappyCompression = 0x1
+};
+
+// Options to control the behavior of a database (passed to DB::Open)
+struct Options {
+ // -------------------
+ // Parameters that affect behavior
+
+ // Comparator used to define the order of keys in the table.
+ // Default: a comparator that uses lexicographic byte-wise ordering
+ //
+ // REQUIRES: The client must ensure that the comparator supplied
+ // here has the same name and orders keys *exactly* the same as the
+ // comparator provided to previous open calls on the same DB.
+ const Comparator* comparator;
+
+ // If true, the database will be created if it is missing.
+ // Default: false
+ bool create_if_missing;
+
+ // If true, an error is raised if the database already exists.
+ // Default: false
+ bool error_if_exists;
+
+ // If true, the implementation will do aggressive checking of the
+ // data it is processing and will stop early if it detects any
+ // errors. This may have unforeseen ramifications: for example, a
+ // corruption of one DB entry may cause a large number of entries to
+ // become unreadable or for the entire DB to become unopenable.
+ // Default: false
+ bool paranoid_checks;
+
+ // Use the specified object to interact with the environment,
+ // e.g. to read/write files, schedule background work, etc.
+ // Default: Env::Default()
+ Env* env;
+
+ // Any internal progress/error information generated by the db will
+ // be written to info_log if it is non-NULL, or to a file stored
+ // in the same directory as the DB contents if info_log is NULL.
+ // Default: NULL
+ Logger* info_log;
+
+ // -------------------
+ // Parameters that affect performance
+
+ // Amount of data to build up in memory (backed by an unsorted log
+ // on disk) before converting to a sorted on-disk file.
+ //
+ // Larger values increase performance, especially during bulk loads.
+ // Up to two write buffers may be held in memory at the same time,
+ // so you may wish to adjust this parameter to control memory usage.
+ // Also, a larger write buffer will result in a longer recovery time
+ // the next time the database is opened.
+ //
+ // Default: 4MB
+ size_t write_buffer_size;
+
+ // Number of open files that can be used by the DB. You may need to
+ // increase this if your database has a large working set (budget
+ // one open file per 2MB of working set).
+ //
+ // Default: 1000
+ int max_open_files;
+
+ // Control over blocks (user data is stored in a set of blocks, and
+ // a block is the unit of reading from disk).
+
+ // If non-NULL, use the specified cache for blocks.
+ // If NULL, leveldb will automatically create and use an 8MB internal cache.
+ // Default: NULL
+ Cache* block_cache;
+
+ // Approximate size of user data packed per block. Note that the
+ // block size specified here corresponds to uncompressed data. The
+ // actual size of the unit read from disk may be smaller if
+ // compression is enabled. This parameter can be changed dynamically.
+ //
+ // Default: 4K
+ size_t block_size;
+
+ // Number of keys between restart points for delta encoding of keys.
+ // This parameter can be changed dynamically. Most clients should
+ // leave this parameter alone.
+ //
+ // Default: 16
+ int block_restart_interval;
+
+ // Compress blocks using the specified compression algorithm. This
+ // parameter can be changed dynamically.
+ //
+ // Default: kSnappyCompression, which gives lightweight but fast
+ // compression.
+ //
+ // Typical speeds of kSnappyCompression on an Intel(R) Core(TM)2 2.4GHz:
+ // ~200-500MB/s compression
+ // ~400-800MB/s decompression
+ // Note that these speeds are significantly faster than most
+ // persistent storage speeds, and therefore it is typically never
+ // worth switching to kNoCompression. Even if the input data is
+ // incompressible, the kSnappyCompression implementation will
+ // efficiently detect that and will switch to uncompressed mode.
+ CompressionType compression;
+
+ // If non-NULL, use the specified filter policy to reduce disk reads.
+ // Many applications will benefit from passing the result of
+ // NewBloomFilterPolicy() here.
+ //
+ // Default: NULL
+ const FilterPolicy* filter_policy;
+
+ // Create an Options object with default values for all fields.
+ Options();
+};
+
+// Options that control read operations
+struct ReadOptions {
+ // If true, all data read from underlying storage will be
+ // verified against corresponding checksums.
+ // Default: false
+ bool verify_checksums;
+
+ // Should the data read for this iteration be cached in memory?
+ // Callers may wish to set this field to false for bulk scans.
+ // Default: true
+ bool fill_cache;
+
+ // If "snapshot" is non-NULL, read as of the supplied snapshot
+ // (which must belong to the DB that is being read and which must
+ // not have been released). If "snapshot" is NULL, use an impliicit
+ // snapshot of the state at the beginning of this read operation.
+ // Default: NULL
+ const Snapshot* snapshot;
+
+ ReadOptions()
+ : verify_checksums(false),
+ fill_cache(true),
+ snapshot(NULL) {
+ }
+};
+
+// Options that control write operations
+struct WriteOptions {
+ // If true, the write will be flushed from the operating system
+ // buffer cache (by calling WritableFile::Sync()) before the write
+ // is considered complete. If this flag is true, writes will be
+ // slower.
+ //
+ // If this flag is false, and the machine crashes, some recent
+ // writes may be lost. Note that if it is just the process that
+ // crashes (i.e., the machine does not reboot), no writes will be
+ // lost even if sync==false.
+ //
+ // In other words, a DB write with sync==false has similar
+ // crash semantics as the "write()" system call. A DB write
+ // with sync==true has similar crash semantics to a "write()"
+ // system call followed by "fsync()".
+ //
+ // Default: false
+ bool sync;
+
+ WriteOptions()
+ : sync(false) {
+ }
+};
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_OPTIONS_H_
diff --git a/api/leveldb/include/slice.h b/api/leveldb/include/slice.h
new file mode 100644
index 00000000000..bc367986f7e
--- /dev/null
+++ b/api/leveldb/include/slice.h
@@ -0,0 +1,109 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// Slice is a simple structure containing a pointer into some external
+// storage and a size. The user of a Slice must ensure that the slice
+// is not used after the corresponding external storage has been
+// deallocated.
+//
+// Multiple threads can invoke const methods on a Slice without
+// external synchronization, but if any of the threads may call a
+// non-const method, all threads accessing the same Slice must use
+// external synchronization.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_SLICE_H_
+#define STORAGE_LEVELDB_INCLUDE_SLICE_H_
+
+#include <assert.h>
+#include <stddef.h>
+#include <string.h>
+#include <string>
+
+namespace leveldb {
+
+class Slice {
+ public:
+ // Create an empty slice.
+ Slice() : data_(""), size_(0) { }
+
+ // Create a slice that refers to d[0,n-1].
+ Slice(const char* d, size_t n) : data_(d), size_(n) { }
+
+ // Create a slice that refers to the contents of "s"
+ Slice(const std::string& s) : data_(s.data()), size_(s.size()) { }
+
+ // Create a slice that refers to s[0,strlen(s)-1]
+ Slice(const char* s) : data_(s), size_(strlen(s)) { }
+
+ // Return a pointer to the beginning of the referenced data
+ const char* data() const { return data_; }
+
+ // Return the length (in bytes) of the referenced data
+ size_t size() const { return size_; }
+
+ // Return true iff the length of the referenced data is zero
+ bool empty() const { return size_ == 0; }
+
+ // Return the ith byte in the referenced data.
+ // REQUIRES: n < size()
+ char operator[](size_t n) const {
+ assert(n < size());
+ return data_[n];
+ }
+
+ // Change this slice to refer to an empty array
+ void clear() { data_ = ""; size_ = 0; }
+
+ // Drop the first "n" bytes from this slice.
+ void remove_prefix(size_t n) {
+ assert(n <= size());
+ data_ += n;
+ size_ -= n;
+ }
+
+ // Return a string that contains the copy of the referenced data.
+ std::string ToString() const { return std::string(data_, size_); }
+
+ // Three-way comparison. Returns value:
+ // < 0 iff "*this" < "b",
+ // == 0 iff "*this" == "b",
+ // > 0 iff "*this" > "b"
+ int compare(const Slice& b) const;
+
+ // Return true iff "x" is a prefix of "*this"
+ bool starts_with(const Slice& x) const {
+ return ((size_ >= x.size_) &&
+ (memcmp(data_, x.data_, x.size_) == 0));
+ }
+
+ private:
+ const char* data_;
+ size_t size_;
+
+ // Intentionally copyable
+};
+
+inline bool operator==(const Slice& x, const Slice& y) {
+ return ((x.size() == y.size()) &&
+ (memcmp(x.data(), y.data(), x.size()) == 0));
+}
+
+inline bool operator!=(const Slice& x, const Slice& y) {
+ return !(x == y);
+}
+
+inline int Slice::compare(const Slice& b) const {
+ const size_t min_len = (size_ < b.size_) ? size_ : b.size_;
+ int r = memcmp(data_, b.data_, min_len);
+ if (r == 0) {
+ if (size_ < b.size_) r = -1;
+ else if (size_ > b.size_) r = +1;
+ }
+ return r;
+}
+
+} // namespace leveldb
+
+
+#endif // STORAGE_LEVELDB_INCLUDE_SLICE_H_
diff --git a/api/leveldb/include/status.h b/api/leveldb/include/status.h
new file mode 100644
index 00000000000..11dbd4b47ed
--- /dev/null
+++ b/api/leveldb/include/status.h
@@ -0,0 +1,106 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// A Status encapsulates the result of an operation. It may indicate success,
+// or it may indicate an error with an associated error message.
+//
+// Multiple threads can invoke const methods on a Status without
+// external synchronization, but if any of the threads may call a
+// non-const method, all threads accessing the same Status must use
+// external synchronization.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_STATUS_H_
+#define STORAGE_LEVELDB_INCLUDE_STATUS_H_
+
+#include <string>
+#include "leveldb/slice.h"
+
+namespace leveldb {
+
+class Status {
+ public:
+ // Create a success status.
+ Status() : state_(NULL) { }
+ ~Status() { delete[] state_; }
+
+ // Copy the specified status.
+ Status(const Status& s);
+ void operator=(const Status& s);
+
+ // Return a success status.
+ static Status OK() { return Status(); }
+
+ // Return error status of an appropriate type.
+ static Status NotFound(const Slice& msg, const Slice& msg2 = Slice()) {
+ return Status(kNotFound, msg, msg2);
+ }
+ static Status Corruption(const Slice& msg, const Slice& msg2 = Slice()) {
+ return Status(kCorruption, msg, msg2);
+ }
+ static Status NotSupported(const Slice& msg, const Slice& msg2 = Slice()) {
+ return Status(kNotSupported, msg, msg2);
+ }
+ static Status InvalidArgument(const Slice& msg, const Slice& msg2 = Slice()) {
+ return Status(kInvalidArgument, msg, msg2);
+ }
+ static Status IOError(const Slice& msg, const Slice& msg2 = Slice()) {
+ return Status(kIOError, msg, msg2);
+ }
+
+ // Returns true iff the status indicates success.
+ bool ok() const { return (state_ == NULL); }
+
+ // Returns true iff the status indicates a NotFound error.
+ bool IsNotFound() const { return code() == kNotFound; }
+
+ // Returns true iff the status indicates a Corruption error.
+ bool IsCorruption() const { return code() == kCorruption; }
+
+ // Returns true iff the status indicates an IOError.
+ bool IsIOError() const { return code() == kIOError; }
+
+ // Return a string representation of this status suitable for printing.
+ // Returns the string "OK" for success.
+ std::string ToString() const;
+
+ private:
+ // OK status has a NULL state_. Otherwise, state_ is a new[] array
+ // of the following form:
+ // state_[0..3] == length of message
+ // state_[4] == code
+ // state_[5..] == message
+ const char* state_;
+
+ enum Code {
+ kOk = 0,
+ kNotFound = 1,
+ kCorruption = 2,
+ kNotSupported = 3,
+ kInvalidArgument = 4,
+ kIOError = 5
+ };
+
+ Code code() const {
+ return (state_ == NULL) ? kOk : static_cast<Code>(state_[4]);
+ }
+
+ Status(Code code, const Slice& msg, const Slice& msg2);
+ static const char* CopyState(const char* s);
+};
+
+inline Status::Status(const Status& s) {
+ state_ = (s.state_ == NULL) ? NULL : CopyState(s.state_);
+}
+inline void Status::operator=(const Status& s) {
+ // The following condition catches both aliasing (when this == &s),
+ // and the common case where both s and *this are ok.
+ if (state_ != s.state_) {
+ delete[] state_;
+ state_ = (s.state_ == NULL) ? NULL : CopyState(s.state_);
+ }
+}
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_STATUS_H_
diff --git a/api/leveldb/include/table.h b/api/leveldb/include/table.h
new file mode 100644
index 00000000000..a9746c3f5ea
--- /dev/null
+++ b/api/leveldb/include/table.h
@@ -0,0 +1,85 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_TABLE_H_
+#define STORAGE_LEVELDB_INCLUDE_TABLE_H_
+
+#include <stdint.h>
+#include "leveldb/iterator.h"
+
+namespace leveldb {
+
+class Block;
+class BlockHandle;
+class Footer;
+struct Options;
+class RandomAccessFile;
+struct ReadOptions;
+class TableCache;
+
+// A Table is a sorted map from strings to strings. Tables are
+// immutable and persistent. A Table may be safely accessed from
+// multiple threads without external synchronization.
+class Table {
+ public:
+ // Attempt to open the table that is stored in bytes [0..file_size)
+ // of "file", and read the metadata entries necessary to allow
+ // retrieving data from the table.
+ //
+ // If successful, returns ok and sets "*table" to the newly opened
+ // table. The client should delete "*table" when no longer needed.
+ // If there was an error while initializing the table, sets "*table"
+ // to NULL and returns a non-ok status. Does not take ownership of
+ // "*source", but the client must ensure that "source" remains live
+ // for the duration of the returned table's lifetime.
+ //
+ // *file must remain live while this Table is in use.
+ static Status Open(const Options& options,
+ RandomAccessFile* file,
+ uint64_t file_size,
+ Table** table);
+
+ ~Table();
+
+ // Returns a new iterator over the table contents.
+ // The result of NewIterator() is initially invalid (caller must
+ // call one of the Seek methods on the iterator before using it).
+ Iterator* NewIterator(const ReadOptions&) const;
+
+ // Given a key, return an approximate byte offset in the file where
+ // the data for that key begins (or would begin if the key were
+ // present in the file). The returned value is in terms of file
+ // bytes, and so includes effects like compression of the underlying data.
+ // E.g., the approximate offset of the last key in the table will
+ // be close to the file length.
+ uint64_t ApproximateOffsetOf(const Slice& key) const;
+
+ private:
+ struct Rep;
+ Rep* rep_;
+
+ explicit Table(Rep* rep) { rep_ = rep; }
+ static Iterator* BlockReader(void*, const ReadOptions&, const Slice&);
+
+ // Calls (*handle_result)(arg, ...) with the entry found after a call
+ // to Seek(key). May not make such a call if filter policy says
+ // that key is not present.
+ friend class TableCache;
+ Status InternalGet(
+ const ReadOptions&, const Slice& key,
+ void* arg,
+ void (*handle_result)(void* arg, const Slice& k, const Slice& v));
+
+
+ void ReadMeta(const Footer& footer);
+ void ReadFilter(const Slice& filter_handle_value);
+
+ // No copying allowed
+ Table(const Table&);
+ void operator=(const Table&);
+};
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_TABLE_H_
diff --git a/api/leveldb/include/table_builder.h b/api/leveldb/include/table_builder.h
new file mode 100644
index 00000000000..5fd1dc71f1c
--- /dev/null
+++ b/api/leveldb/include/table_builder.h
@@ -0,0 +1,92 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// TableBuilder provides the interface used to build a Table
+// (an immutable and sorted map from keys to values).
+//
+// Multiple threads can invoke const methods on a TableBuilder without
+// external synchronization, but if any of the threads may call a
+// non-const method, all threads accessing the same TableBuilder must use
+// external synchronization.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_
+#define STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_
+
+#include <stdint.h>
+#include "leveldb/options.h"
+#include "leveldb/status.h"
+
+namespace leveldb {
+
+class BlockBuilder;
+class BlockHandle;
+class WritableFile;
+
+class TableBuilder {
+ public:
+ // Create a builder that will store the contents of the table it is
+ // building in *file. Does not close the file. It is up to the
+ // caller to close the file after calling Finish().
+ TableBuilder(const Options& options, WritableFile* file);
+
+ // REQUIRES: Either Finish() or Abandon() has been called.
+ ~TableBuilder();
+
+ // Change the options used by this builder. Note: only some of the
+ // option fields can be changed after construction. If a field is
+ // not allowed to change dynamically and its value in the structure
+ // passed to the constructor is different from its value in the
+ // structure passed to this method, this method will return an error
+ // without changing any fields.
+ Status ChangeOptions(const Options& options);
+
+ // Add key,value to the table being constructed.
+ // REQUIRES: key is after any previously added key according to comparator.
+ // REQUIRES: Finish(), Abandon() have not been called
+ void Add(const Slice& key, const Slice& value);
+
+ // Advanced operation: flush any buffered key/value pairs to file.
+ // Can be used to ensure that two adjacent entries never live in
+ // the same data block. Most clients should not need to use this method.
+ // REQUIRES: Finish(), Abandon() have not been called
+ void Flush();
+
+ // Return non-ok iff some error has been detected.
+ Status status() const;
+
+ // Finish building the table. Stops using the file passed to the
+ // constructor after this function returns.
+ // REQUIRES: Finish(), Abandon() have not been called
+ Status Finish();
+
+ // Indicate that the contents of this builder should be abandoned. Stops
+ // using the file passed to the constructor after this function returns.
+ // If the caller is not going to call Finish(), it must call Abandon()
+ // before destroying this builder.
+ // REQUIRES: Finish(), Abandon() have not been called
+ void Abandon();
+
+ // Number of calls to Add() so far.
+ uint64_t NumEntries() const;
+
+ // Size of the file generated so far. If invoked after a successful
+ // Finish() call, returns the size of the final generated file.
+ uint64_t FileSize() const;
+
+ private:
+ bool ok() const { return status().ok(); }
+ void WriteBlock(BlockBuilder* block, BlockHandle* handle);
+ void WriteRawBlock(const Slice& data, CompressionType, BlockHandle* handle);
+
+ struct Rep;
+ Rep* rep_;
+
+ // No copying allowed
+ TableBuilder(const TableBuilder&);
+ void operator=(const TableBuilder&);
+};
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_
diff --git a/api/leveldb/include/write_batch.h b/api/leveldb/include/write_batch.h
new file mode 100644
index 00000000000..ee9aab68e0d
--- /dev/null
+++ b/api/leveldb/include/write_batch.h
@@ -0,0 +1,64 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// WriteBatch holds a collection of updates to apply atomically to a DB.
+//
+// The updates are applied in the order in which they are added
+// to the WriteBatch. For example, the value of "key" will be "v3"
+// after the following batch is written:
+//
+// batch.Put("key", "v1");
+// batch.Delete("key");
+// batch.Put("key", "v2");
+// batch.Put("key", "v3");
+//
+// Multiple threads can invoke const methods on a WriteBatch without
+// external synchronization, but if any of the threads may call a
+// non-const method, all threads accessing the same WriteBatch must use
+// external synchronization.
+
+#ifndef STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
+#define STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
+
+#include <string>
+#include "leveldb/status.h"
+
+namespace leveldb {
+
+class Slice;
+
+class WriteBatch {
+ public:
+ WriteBatch();
+ ~WriteBatch();
+
+ // Store the mapping "key->value" in the database.
+ void Put(const Slice& key, const Slice& value);
+
+ // If the database contains a mapping for "key", erase it. Else do nothing.
+ void Delete(const Slice& key);
+
+ // Clear all updates buffered in this batch.
+ void Clear();
+
+ // Support for iterating over the contents of a batch.
+ class Handler {
+ public:
+ virtual ~Handler();
+ virtual void Put(const Slice& key, const Slice& value) = 0;
+ virtual void Delete(const Slice& key) = 0;
+ };
+ Status Iterate(Handler* handler) const;
+
+ private:
+ friend class WriteBatchInternal;
+
+ std::string rep_; // See comment in write_batch.cc for the format of rep_
+
+ // Intentionally copyable
+};
+
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
diff --git a/api/leveldb/leveldb_wt.h b/api/leveldb/leveldb_wt.h
index 759e8a5513d..434706240a9 100644
--- a/api/leveldb/leveldb_wt.h
+++ b/api/leveldb/leveldb_wt.h
@@ -12,16 +12,16 @@
#include <hyperleveldb/table_builder.h>
#include <hyperleveldb/write_batch.h>
#else
-#include <leveldb/cache.h>
-#include <leveldb/comparator.h>
-#include <leveldb/db.h>
-#include <leveldb/env.h>
-#include <leveldb/filter_policy.h>
-#include <leveldb/slice.h>
-#include <leveldb/slice.h>
-#include <leveldb/status.h>
-#include <leveldb/table_builder.h>
-#include <leveldb/write_batch.h>
+#include "cache.h"
+#include "comparator.h"
+#include "db.h"
+#include "env.h"
+#include "filter_policy.h"
+#include "slice.h"
+#include "slice.h"
+#include "status.h"
+#include "table_builder.h"
+#include "write_batch.h"
#endif
#include "wiredtiger.h"