Release 1.18v1.18

Changes are:

* Update version number to 1.18
* Replace the basic fprintf call with a call to fwrite in order to
  work around the apparent compiler optimization/rewrite failure that we are
  seeing with the new toolchain/iOS SDKs provided with Xcode6 and iOS8.
* Fix ALL the header guards.
* Createed a README.md with the LevelDB project description.
* A new CONTRIBUTING file.
* Don't implicitly convert uint64_t to size_t or int.  Either preserve it as
  uint64_t, or explicitly cast. This fixes MSVC warnings about possible value
  truncation when compiling this code in Chromium.
* Added a DumpFile() library function that encapsulates the guts of the
  "leveldbutil dump" command. This will allow clients to dump
  data to their log files instead of stdout. It will also allow clients to
  supply their own environment.
* leveldb: Remove unused function 'ConsumeChar'.
* leveldbutil: Remove unused member variables from WriteBatchItemPrinter.
* OpenBSD, NetBSD and DragonflyBSD have _LITTLE_ENDIAN, so define
  PLATFORM_IS_LITTLE_ENDIAN like on FreeBSD. This fixes:
   * issue #143
   * issue #198
   * issue #249
* Switch from <cstdatomic> to <atomic>. The former never made it into the
  standard and doesn't exist in modern gcc versions at all.  The later contains
  everything that leveldb was using from the former.
  This problem was noticed when porting to Portable Native Client where no memory
  barrier is defined.  The fact that <cstdatomic> is missing normally goes
  unnoticed since memory barriers are defined for most architectures.
* Make Hash() treat its input as unsigned.  Before this change LevelDB files
  from platforms with different signedness of char were not compatible. This
  change fixes: issue #243
* Verify checksums of index/meta/filter blocks when paranoid_checks set.
* Invoke all tools for iOS with xcrun. (This was causing problems with the new
  XCode 5.1.1 image on pulse.)
* include <sys/stat.h> only once, and fix the following linter warning:
  "Found C system header after C++ system header"
* When encountering a corrupted table file, return Status::Corruption instead of
  Status::InvalidArgument.
* Support cygwin as build platform, patch is from https://code.google.com/p/leveldb/issues/detail?id=188
* Fix typo, merge patch from https://code.google.com/p/leveldb/issues/detail?id=159
* Fix typos and comments, and address the following two issues:
  * issue #166
  * issue #241
* Add missing db synchronize after "fillseq" in the benchmark.
* Removed unused variable in SeekRandom: value (issue #201)

4 files changed, 15 insertions, 5 deletions

diff --git a/table/block.cc b/table/block.cc
index 79ea9d9..43e402c 100644
--- a/table/block.cc
+++ b/table/block.cc
@@ -46,7 +46,7 @@ Block::~Block() {
 // Helper routine: decode the next block entry starting at "p",
 // storing the number of shared key bytes, non_shared key bytes,
 // and the length of the value in "*shared", "*non_shared", and
-// "*value_length", respectively.  Will not derefence past "limit".
+// "*value_length", respectively.  Will not dereference past "limit".
 //
 // If any errors are detected, returns NULL.  Otherwise, returns a
 // pointer to the key delta (just past the three decoded values).
diff --git a/table/block_builder.h b/table/block_builder.h
index 5b545bd..4fbcb33 100644
--- a/table/block_builder.h
+++ b/table/block_builder.h
@@ -21,7 +21,7 @@ class BlockBuilder {
   // Reset the contents as if the BlockBuilder was just constructed.
   void Reset();
 
-  // REQUIRES: Finish() has not been callled since the last call to Reset().
+  // REQUIRES: Finish() has not been called since the last call to Reset().
   // REQUIRES: key is larger than any previously added key
   void Add(const Slice& key, const Slice& value);
 
diff --git a/table/format.cc b/table/format.cc
index cda1dec..aa63144 100644
--- a/table/format.cc
+++ b/table/format.cc
@@ -48,7 +48,7 @@ Status Footer::DecodeFrom(Slice* input) {
   const uint64_t magic = ((static_cast<uint64_t>(magic_hi) << 32) |
                           (static_cast<uint64_t>(magic_lo)));
   if (magic != kTableMagicNumber) {
-    return Status::InvalidArgument("not an sstable (bad magic number)");
+    return Status::Corruption("not an sstable (bad magic number)");
   }
 
   Status result = metaindex_handle_.DecodeFrom(input);
diff --git a/table/table.cc b/table/table.cc
index 71c1756..dff8a82 100644
--- a/table/table.cc
+++ b/table/table.cc
@@ -41,7 +41,7 @@ Status Table::Open(const Options& options,
                    Table** table) {
   *table = NULL;
   if (size < Footer::kEncodedLength) {
-    return Status::InvalidArgument("file is too short to be an sstable");
+    return Status::Corruption("file is too short to be an sstable");
   }
 
   char footer_space[Footer::kEncodedLength];
@@ -58,7 +58,11 @@ Status Table::Open(const Options& options,
   BlockContents contents;
   Block* index_block = NULL;
   if (s.ok()) {
-    s = ReadBlock(file, ReadOptions(), footer.index_handle(), &contents);
+    ReadOptions opt;
+    if (options.paranoid_checks) {
+      opt.verify_checksums = true;
+    }
+    s = ReadBlock(file, opt, footer.index_handle(), &contents);
     if (s.ok()) {
       index_block = new Block(contents);
     }
@@ -92,6 +96,9 @@ void Table::ReadMeta(const Footer& footer) {
   // TODO(sanjay): Skip this if footer.metaindex_handle() size indicates
   // it is an empty block.
   ReadOptions opt;
+  if (rep_->options.paranoid_checks) {
+    opt.verify_checksums = true;
+  }
   BlockContents contents;
   if (!ReadBlock(rep_->file, opt, footer.metaindex_handle(), &contents).ok()) {
     // Do not propagate errors since meta info is not needed for operation
@@ -120,6 +127,9 @@ void Table::ReadFilter(const Slice& filter_handle_value) {
   // We might want to unify with ReadBlock() if we start
   // requiring checksum verification in Table::Open.
   ReadOptions opt;
+  if (rep_->options.paranoid_checks) {
+    opt.verify_checksums = true;
+  }
   BlockContents block;
   if (!ReadBlock(rep_->file, opt, filter_handle, &block).ok()) {
     return;