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Diffstat (limited to 'ace/Filecache.h')
| -rw-r--r-- | ace/Filecache.h | 355 |
1 files changed, 0 insertions, 355 deletions
diff --git a/ace/Filecache.h b/ace/Filecache.h deleted file mode 100644 index 78bedd38a64..00000000000 --- a/ace/Filecache.h +++ /dev/null @@ -1,355 +0,0 @@ -/* -*- c++ -*- */ - -//============================================================================= -/** - * @file Filecache.h - * - * $Id$ - * - * @author James Hu - */ -//============================================================================= - - -#ifndef ACE_FILECACHE_H -#define ACE_FILECACHE_H -#include "ace/pre.h" - -#include "ace/Mem_Map.h" - -#if !defined (ACE_LACKS_PRAGMA_ONCE) -# pragma once -#endif /* ACE_LACKS_PRAGMA_ONCE */ - -#include "ace/Synch_T.h" -#include "ace/Hash_Map_Manager.h" -#include "ace/SString.h" - -enum ACE_Filecache_Flag -{ - ACE_NOMAP = 0, - ACE_MAPIT = 1 -}; - -class ACE_Filecache_Object; - -/** - * @class ACE_Filecache_Handle - * - * @brief Abstraction over a real file. This is meant to be the entry - * point into the Cached Virtual Filesystem. - * - * This is a cached filesystem implementation based loosely on the - * implementation of JAWS_File. The interfaces will be nearly the - * same. The under-the-hood implementation should hopefully be a - * much faster thing. - * These will be given their own implementations later. For now, we - * borrow the implementation provided by JAWS. - * On creation, the cache is checked, and reference count is - * incremented. On destruction, reference count is decremented. If - * the reference count is 0, the file is removed from the cache. - * E.g. 1, - * { - * ACE_Filecache_Handle foo("foo.html"); - * this->peer ().send (foo.address (), foo.size ()); - * } - * E.g. 2, - * { - * ACE_Filecache_Handle foo("foo.html"); - * io->transmitfile (foo.handle (), this->peer ().handle ()); - * } - * E.g. 3, - * { - * ACE_Filecache_Handle foo("foo.html", content_length); - * this->peer ().recv (foo.address (), content_length); - * } - * TODO: - */ -class ACE_Export ACE_Filecache_Handle -{ - // (1) Get rid of the useless copying of files when reading. - // Although it does make sure the file you send isn't being changed, - // it doesn't make sure the file is in a sensible state before - // sending it. - // - // Alternative: if the file get's trashed while it is being shipped, - // let the client request the file again. The cache should have an - // updated copy by that point. - // - // (2) Use hashing for locating files. This means I need a hastable - // implementation with buckets. - // - // (3) Only lock when absolutely necessary. JAWS_Virtual_Filesystem was - // rather conservative, but for some reason it still ran into problems. - // Since this design should be simpler, problems should be easier to spot. - // -public: - - /// Query cache for file, and acquire it. Assumes the file is being - /// opened for reading. - ACE_Filecache_Handle (const ACE_TCHAR *filename, - ACE_Filecache_Flag mapit = ACE_MAPIT); - - /** - * Create new entry, and acquire it. Presence of SIZE assumes the - * file is being opened for writing. If SIZE is zero, assumes the - * file is to be removed from the cache. - */ - ACE_Filecache_Handle (const ACE_TCHAR *filename, - int size, - ACE_Filecache_Flag mapit = ACE_MAPIT); - - /// Closes any open handles, release acquired file. - ~ACE_Filecache_Handle (void); - - /// Base address of memory mapped file. - void *address (void) const; - - /// A handle (e.g., UNIX file descriptor, or NT file handle). - ACE_HANDLE handle (void) const; - - /// Any associated error in handle creation and acquisition. - int error (void) const; - - /// The size of the file. - off_t size (void) const; - -protected: - /// Default do nothing constructor. Prevent it from being called. - ACE_Filecache_Handle (void); - - /// Common initializations for constructors. - void init (void); - -public: - /// These come from ACE_Filecache_Object, which is an internal class. - enum - { - ACE_SUCCESS = 0, - ACE_ACCESS_FAILED, - ACE_OPEN_FAILED, - ACE_COPY_FAILED, - ACE_STAT_FAILED, - ACE_MEMMAP_FAILED, - ACE_WRITE_FAILED - }; - -private: - /// A reference to the low level instance. - ACE_Filecache_Object *file_; - - /// A <dup>'d version of the one from <file_>. - ACE_HANDLE handle_; - - int mapit_; -}; - -#if defined (ACE_HAS_TEMPLATE_SPECIALIZATION) -typedef ACE_Hash_Map_Entry<const ACE_TCHAR *, ACE_Filecache_Object *> - ACE_Filecache_Hash_Entry; - -typedef ACE_Hash_Map_Manager<const ACE_TCHAR *, ACE_Filecache_Object *, ACE_Null_Mutex> - ACE_Filecache_Hash; -#else -typedef ACE_Hash_Map_Entry<ACE_TString, ACE_Filecache_Object *> - ACE_Filecache_Hash_Entry; - -typedef ACE_Hash_Map_Manager<ACE_TString, ACE_Filecache_Object *, ACE_Null_Mutex> - ACE_Filecache_Hash; -#endif /* ACE_HAS_TEMPLATE_SPECIALIZATION */ - -/** - * @class ACE_Filecache - * - * @brief A hash table holding the information about entry point into - * the Cached Virtual Filesystem. On insertion, the reference - * count is incremented. On destruction, reference count is - * decremented. - */ -class ACE_Export ACE_Filecache -{ -public: - /// Singleton pattern. - static ACE_Filecache *instance (void); - - ~ACE_Filecache (void); - - /// Returns 0 if the file associated with ``filename'' is in the cache, - /// or -1 if not. - int find (const ACE_TCHAR *filename); - - /// Return the file associated with ``filename'' if it is in the cache, - /// or create if not. - ACE_Filecache_Object *fetch (const ACE_TCHAR *filename, int mapit = 1); - - /// Remove the file associated with ``filename'' from the cache. - ACE_Filecache_Object *remove (const ACE_TCHAR *filename); - - /// Create a new Filecache_Object, returns it. - ACE_Filecache_Object *create (const ACE_TCHAR *filename, int size); - - /// Release an acquired Filecache_Object, returns it again or NULL if it - /// was deleted. - ACE_Filecache_Object *finish (ACE_Filecache_Object *&new_file); - -protected: - ACE_Filecache_Object *insert_i (const ACE_TCHAR *filename, - ACE_SYNCH_RW_MUTEX &filelock, - int mapit); - ACE_Filecache_Object *remove_i (const ACE_TCHAR *filename); - ACE_Filecache_Object *update_i (const ACE_TCHAR *filename, - ACE_SYNCH_RW_MUTEX &filelock, - int mapit); - -public: - - enum - { - /// For this stupid implementation, use an array. Someday, use a - /// balanced search tree, or real hash table. - ACE_DEFAULT_VIRTUAL_FILESYSTEM_TABLE_SIZE = 512, - - /// This determines the highwater mark in megabytes for the cache. - /// This will be ignored for now. - ACE_DEFAULT_VIRTUAL_FILESYSTEM_CACHE_SIZE = 20 - }; - -protected: - /// Prevent it from being called. - ACE_Filecache (void); - -private: - int size_; - - /// The hash table - ACE_Filecache_Hash hash_; - - /// The reference to the instance - static ACE_Filecache *cvf_; - - // = Synchronization variables. - ACE_SYNCH_RW_MUTEX hash_lock_[ACE_DEFAULT_VIRTUAL_FILESYSTEM_TABLE_SIZE]; - ACE_SYNCH_RW_MUTEX file_lock_[ACE_DEFAULT_VIRTUAL_FILESYSTEM_TABLE_SIZE]; -}; - -/** - * @class ACE_Filecache_Object - * - * @brief Abstraction over a real file. This is what the Virtual - * Filesystem contains. This class is not intended for general - * consumption. Please consult a physician before attempting to - * use this class. - */ -class ACE_Export ACE_Filecache_Object -{ -public: - friend class ACE_Filecache; - - /// Creates a file for reading. - ACE_Filecache_Object (const ACE_TCHAR *filename, - ACE_SYNCH_RW_MUTEX &lock, - LPSECURITY_ATTRIBUTES sa = 0, - int mapit = 1); - - /// Creates a file for writing. - ACE_Filecache_Object (const ACE_TCHAR *filename, - off_t size, - ACE_SYNCH_RW_MUTEX &lock, - LPSECURITY_ATTRIBUTES sa = 0); - - /// Only if reference count is zero should this be called. - ~ACE_Filecache_Object (void); - - /// Increment the reference_count_. - int acquire (void); - - /// Decrement the reference_count_. - int release (void); - - // = error_ accessors - int error (void) const; - int error (int error_value, - const ACE_TCHAR *s = ACE_LIB_TEXT ("ACE_Filecache_Object")); - - /// filename_ accessor - const ACE_TCHAR *filename (void) const; - - /// handle_ accessor. - ACE_HANDLE handle (void) const; - - /// Base memory address for memory mapped file. - void *address (void) const; - - /// size_ accessor. - off_t size (void) const; - - /// True if file on disk is newer than cached file. - int update (void) const; - -protected: - /// Prevent from being called. - ACE_Filecache_Object (void); - - /// Common initialization code, - void init (void); - -private: - /// Internal error logging method, no locking. - int error_i (int error_value, - const ACE_TCHAR *s = ACE_LIB_TEXT ("ACE_Filecache_Object")); - -public: - - enum Creation_States - { - ACE_READING = 1, - ACE_WRITING = 2 - }; - - enum Error_Conditions - { - ACE_SUCCESS = 0, - ACE_ACCESS_FAILED, - ACE_OPEN_FAILED, - ACE_COPY_FAILED, - ACE_STAT_FAILED, - ACE_MEMMAP_FAILED, - ACE_WRITE_FAILED - }; - -private: - /// The temporary file name and the real file name. The real file is - /// copied into the temporary file for safety reasons. - ACE_TCHAR *tempname_; - ACE_TCHAR filename_[MAXPATHLEN + 1]; - - /// Holds the memory mapped version of the temporary file. - ACE_Mem_Map mmap_; - - /// The descriptor to the temporary file. - ACE_HANDLE handle_; - - /// Used to compare against the real file to test if an update is needed. - ACE_stat stat_; - off_t size_; - - /// Status indicators. - int action_; - int error_; - - /// If set to 1, means the object is flagged for removal. - int stale_; - - /// Security attribute object. - LPSECURITY_ATTRIBUTES sa_; - - /// The default initializer - ACE_SYNCH_RW_MUTEX junklock_; - - /// Provides a bookkeeping mechanism for users of this object. - ACE_SYNCH_RW_MUTEX &lock_; -}; - - -#include "ace/post.h" -#endif /* ACE_FILECACHE_H */ |