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Diffstat (limited to 'ace/Filecache.h')
| -rw-r--r-- | ace/Filecache.h | 350 |
1 files changed, 0 insertions, 350 deletions
diff --git a/ace/Filecache.h b/ace/Filecache.h deleted file mode 100644 index 5ffdd57a60f..00000000000 --- a/ace/Filecache.h +++ /dev/null @@ -1,350 +0,0 @@ -/* -*- c++ -*- */ -// Hey, Emacs! This is a C++ file! -// $Id$ - -// ============================================================================ -// -// = LIBRARY -// ace -// -// = FILENAME -// Filecache.h -// -// = AUTHOR -// James Hu -// -// ============================================================================ - -#if !defined (ACE_FILECACHE_H) -#define ACE_FILECACHE_H - -#include "ace/Mem_Map.h" -#include "ace/Synch_T.h" -#include "ace/Hash_Map_Manager.h" -#include "ace/SString.h" - -enum ACE_Filecache_Flag -{ - NOMAP = 0, - MAPIT = 1 -}; - -// = Forward declarations. -ACE_DECLARE_EXPORT(class, ACE_Filecache); -ACE_DECLARE_EXPORT(class, ACE_Filecache_Handle); -class ACE_Filecache_Object; - -class ACE_Filecache_Handle -{ - // = TITLE - // Abstraction over a real file. This is meant to be the entry - // point into the Cached Virtual Filesystem. - // - // = DESCRIPTION - // 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: - - // (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: - - ACE_Filecache_Handle (const char *filename, - ACE_Filecache_Flag mapit = MAPIT); - // Query cache for file, and acquire it. Assumes the file is being - // opened for reading. - - ACE_Filecache_Handle (const char *filename, - int size, - ACE_Filecache_Flag mapit = MAPIT); - // Create new entry, and acquire it. Presence of SIZE assumes the - // file is being opened for writing. - - ~ACE_Filecache_Handle (void); - // Closes any open handles, release acquired file. - - void *address (void) const; - // Base address of memory mapped file. - - ACE_HANDLE handle (void) const; - // A handle (e.g., UNIX file descriptor, or NT file handle). - - int error (void) const; - // Any associated error in handle creation and acquisition. - - size_t size (void) const; - // The size of the file. - -protected: - - ACE_Filecache_Handle (void); - // Default do nothing constructor. Prevent it from being called. - - void init (void); - // Common initializations for constructors. - -public: - - // These come from ACE_Filecache_Object, which is an internal class. - enum - { - SUCCESS = 0, - ACCESS_FAILED, - OPEN_FAILED, - COPY_FAILED, - STAT_FAILED, - MEMMAP_FAILED, - WRITE_FAILED - }; - -private: - ACE_Filecache_Object *file_; - // A reference to the low level instance. - - ACE_HANDLE handle_; - // A dup()'d version of the one from this->file_. - - int mapit_; -}; - -#if defined (ACE_HAS_TEMPLATE_SPECIALIZATION) -typedef ACE_Hash_Map_Entry<const char *, ACE_Filecache_Object *> - ACE_Filecache_Hash_Entry; - -typedef ACE_Hash_Map_Manager<const char *, ACE_Filecache_Object *, ACE_Null_Mutex> - ACE_Filecache_Hash; -#else -typedef ACE_Hash_Map_Entry<ACE_CString, ACE_Filecache_Object *> - ACE_Filecache_Hash_Entry; - -typedef ACE_Hash_Map_Manager<ACE_CString, ACE_Filecache_Object *, ACE_Null_Mutex> - ACE_Filecache_Hash; -#endif /* ACE_HAS_TEMPLATE_SPECIALIZATION */ - -class ACE_Filecache -{ - // = TITLE - // 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. -public: - static ACE_Filecache *instance (void); - // Singleton pattern. - - ~ACE_Filecache (void); - - int find (const char *filename); - // Returns 0 if the file associated with ``filename'' is in the cache, - // or -1 if not. - - ACE_Filecache_Object *fetch (const char *filename, int mapit = 1); - // Return the file associated with ``filename'' if it is in the cache, - // or create if not. - - ACE_Filecache_Object *remove (const char *filename); - // Remove the file associated with ``filename'' from the cache. - - ACE_Filecache_Object *create (const char *filename, int size); - // Create a new Filecache_Object, returns it. - - ACE_Filecache_Object *finish (ACE_Filecache_Object *&new_file); - // Release an acquired Filecache_Object, returns it again or NULL if it - // was deleted. - -protected: - ACE_Filecache_Object *insert_i (const char *filename, - ACE_SYNCH_RW_MUTEX &filelock, - int mapit); - ACE_Filecache_Object *remove_i (const char *filename); - ACE_Filecache_Object *update_i (const char *filename, - ACE_SYNCH_RW_MUTEX &filelock, - int mapit); - -public: - - enum - { - DEFAULT_VIRTUAL_FILESYSTEM_TABLE_SIZE = 512, - // For this stupid implementation, use an array. Someday, use a - // balanced search tree, or real hash table. - - DEFAULT_VIRTUAL_FILESYSTEM_CACHE_SIZE = 20 - // This determines the highwater mark in megabytes for the cache. - // This will be ignored for now. - }; - -protected: - ACE_Filecache (void); - // Prevent it from being called. - -private: - int size_; - - ACE_Filecache_Hash hash_; - // The hash table - - static ACE_Filecache *cvf_; - // The reference to the instance - - // = Synchronization variables. - ACE_SYNCH_RW_MUTEX hash_lock_[DEFAULT_VIRTUAL_FILESYSTEM_TABLE_SIZE]; - ACE_SYNCH_RW_MUTEX file_lock_[DEFAULT_VIRTUAL_FILESYSTEM_TABLE_SIZE]; -}; - -class ACE_Filecache_Object -{ - // = TITLE - // 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. -public: - friend class ACE_Filecache; - - ACE_Filecache_Object (const char *filename, - ACE_SYNCH_RW_MUTEX &lock, - LPSECURITY_ATTRIBUTES sa = 0, - int mapit = 1); - // Creates a file for reading. - - ACE_Filecache_Object (const char *filename, - int size, - ACE_SYNCH_RW_MUTEX &lock, - LPSECURITY_ATTRIBUTES sa = 0); - // Creates a file for writing. - - ~ACE_Filecache_Object (void); - // Only if reference count is zero should this be called. - - int acquire (void); - // Increment the reference_count_. - - int release (void); - // Decrement the reference_count_. - - // = error_ accessors - int error (void) const; - int error (int error_value, - const char *s = "ACE_Filecache_Object"); - - const char *filename (void) const; - // filename_ accessor - - ACE_HANDLE handle (void) const; - // handle_ accessor. - - void *address (void) const; - // Base memory address for memory mapped file. - - size_t size (void) const; - // size_ accessor. - - int update (void) const; - // True if file on disk is newer than cached file. - -protected: - ACE_Filecache_Object (void); - // Prevent from being called. - - void init (void); - // Common initialization code, - -private: - int error_i (int error_value, - const char *s = "ACE_Filecache_Object"); - // Internal error logging method, no locking. - -public: - - enum Creation_States - { - READING = 1, - WRITING = 2 - }; - - enum Error_Conditions - { - SUCCESS = 0, - ACCESS_FAILED, - OPEN_FAILED, - COPY_FAILED, - STAT_FAILED, - MEMMAP_FAILED, - WRITE_FAILED - }; - -private: - char *tempname_; - char filename_[MAXPATHLEN + 1]; - // The temporary file name and the real file name. The real file is - // copied into the temporary file for safety reasons. - - ACE_Mem_Map mmap_; - ACE_HANDLE handle_; - // mmap_ holds the memory mapped version of the temporary file. - // handle_ is the descriptor to the temporary file. - - struct stat stat_; - size_t size_; - // Used to compare against the real file to test if an update is needed. - - int action_; - int error_; - // Status indicators. - - int stale_; - // If set to 1, means the object is flagged for removal. - - LPSECURITY_ATTRIBUTES sa_; - // Security attribute object. - - ACE_SYNCH_RW_MUTEX junklock_; - ACE_SYNCH_RW_MUTEX &lock_; - // lock_ provides a bookkeeping mechanism for users of this object. - // junklock_ is the default initializer -}; - - -#endif /* ACE_FILECACHE_H */ |