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GNU CommonC++
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This class defines a database I/O file service that can be shared by multiple processes. More...
#include <file.h>
Public Member Functions | |
| SharedFile (const char *path) | |
| Open or create a new database file. | |
| SharedFile (const SharedFile &file) | |
| Create a shared file as a duplicate of an existing shared file. | |
| virtual | ~SharedFile () |
| Close and finish a database file. | |
| Error | restart (void) |
| Restart an existing database; close and re-open. | |
| Error | fetch (char *address=NULL, ccxx_size_t length=0, off_t position=-1) |
| Lock and Fetch a portion of the file into physical memory. | |
| Error | update (char *address=NULL, ccxx_size_t length=0, off_t position=-1) |
| Update a portion of a file from physical memory. | |
| Error | clear (ccxx_size_t length=0, off_t pos=-1) |
| Clear a lock held from a previous fetch operation without updating. | |
| Error | append (char *address=NULL, ccxx_size_t length=0) |
| Add new data to the end of the file. | |
| off_t | getPosition (void) |
| Fetch the current file position marker for this thread. | |
| bool | operator++ (void) |
| bool | operator-- (void) |
Public Member Functions inherited from ost::RandomFile | |
| virtual | ~RandomFile () |
| Destroy a random access file or it's derived class. | |
| bool | initial (void) |
| This method should be called right after a RandomFile derived object has been created. | |
| off_t | getCapacity (void) |
| Get current file capacity. | |
| Error | getErrorNumber (void) |
| Return current error id. | |
| char * | getErrorString (void) |
| Return current error string. | |
| bool | operator! (void) |
Additional Inherited Members | ||
Public Types inherited from ost::File | ||
| enum | Error { errSuccess = 0 , errNotOpened , errMapFailed , errInitFailed , errOpenDenied , errOpenFailed , errOpenInUse , errReadInterrupted , errReadIncomplete , errReadFailure , errWriteInterrupted , errWriteIncomplete , errWriteFailure , errLockFailure , errExtended } | |
| enum | Access { accessReadOnly = O_RDONLY , accessWriteOnly = O_WRONLY , accessReadWrite = O_RDWR } | |
| enum | Open { openReadOnly = O_RDONLY , openWriteOnly = O_WRONLY , openReadWrite = O_RDWR , openAppend = O_WRONLY | O_APPEND , openSync = O_RDWR , openTruncate = O_RDWR | O_TRUNC } | |
| enum | Attr { attrInvalid = 0 , attrPrivate = 0400 | 0200 , attrGroup = attrPrivate | 0040 | 0020 , attrPublic = attrGroup | 0004 | 0002 } | |
| enum | Mapping { mappedRead = accessReadOnly , mappedWrite = accessWriteOnly , mappedReadWrite = accessReadWrite } | |
| enum | Complete { completionImmediate , completionDelayed , completionDeferred } | |
| typedef enum Error | Error | |
| typedef enum Access | Access | |
| typedef enum Open | Open | |
| typedef enum Attr | Attr | |
| typedef enum Complete | Complete | |
| typedef enum Mapping | Mapping | |
Static Public Member Functions inherited from ost::File | ||
| static const char * | getExtension (const char *path) | |
| static const char * | getFilename (const char *path) | |
| static char * | getFilename (const char *path, char *buffer, size_t size=64) | |
| static char * | getDirname (const char *path, char *buffer, size_t size=256) | |
| static char * | getRealpath (const char *path, char *buffer, size_t size=256) | |
Protected Types inherited from ost::File | ||
| typedef struct ost::File::_fcb | fcb_t | |
| enum | Error { errSuccess = 0 , errNotOpened , errMapFailed , errInitFailed , errOpenDenied , errOpenFailed , errOpenInUse , errReadInterrupted , errReadIncomplete , errReadFailure , errWriteInterrupted , errWriteIncomplete , errWriteFailure , errLockFailure , errExtended } | |
| enum | Access { accessReadOnly = O_RDONLY , accessWriteOnly = O_WRONLY , accessReadWrite = O_RDWR } | |
| enum | Open { openReadOnly = O_RDONLY , openWriteOnly = O_WRONLY , openReadWrite = O_RDWR , openAppend = O_WRONLY | O_APPEND , openSync = O_RDWR , openTruncate = O_RDWR | O_TRUNC } | |
| enum | Attr { attrInvalid = 0 , attrPrivate = 0400 | 0200 , attrGroup = attrPrivate | 0040 | 0020 , attrPublic = attrGroup | 0004 | 0002 } | |
| enum | Mapping { mappedRead = accessReadOnly , mappedWrite = accessWriteOnly , mappedReadWrite = accessReadWrite } | |
| enum | Complete { completionImmediate , completionDelayed , completionDeferred } | |
| typedef enum Error | Error | |
| typedef enum Access | Access | |
| typedef enum Open | Open | |
| typedef enum Attr | Attr | |
| typedef enum Complete | Complete | |
| typedef enum Mapping | Mapping | |
Protected Member Functions inherited from ost::RandomFile | ||
| RandomFile (const char *name=NULL) | ||
| Create an unopened random access file. | ||
| RandomFile (const RandomFile &rf) | ||
| Default copy constructor. | ||
| Error | error (Error errid, char *errstr=NULL) | |
| Post an error event. | ||
| Error | error (char *err) | |
| Post an extended string error message. | ||
| void | setError (bool enable) | |
| Used to enable or disable throwing of exceptions on errors. | ||
| Error | setCompletion (Complete mode) | |
| Used to set file completion modes. | ||
| void | setTemporary (bool enable) | |
| Used to set the temporary attribute for the file. | ||
| virtual Attr | initialize (void) | |
| This method is used to initialize a newly created file as indicated by the "initial" flag. | ||
| void | final (void) | |
| Close the file. | ||
Protected Member Functions inherited from ost::Mutex | ||
| Mutex (const char *name=NULL) | ||
| The mutex is always initialized as a recursive entity. | ||
| virtual | ~Mutex () | |
| Destroying the mutex removes any system resources associated with it. | ||
| void | nameMutex (const char *name) | |
| Enable setting of mutex name for deadlock debug. | ||
| void | enterMutex (void) | |
| Entering a Mutex locks the mutex for the current thread. | ||
| void | enter (void) | |
| Future abi will use enter/leave/test members. | ||
| void | leave (void) | |
| Future abi will use enter/leave/test members. | ||
| bool | test (void) | |
| Future abi will use enter/leave/test members. | ||
| bool | tryEnterMutex (void) | |
| Tries to lock the mutex for the current thread. | ||
| void | leaveMutex (void) | |
| Leaving a mutex frees that mutex for use by another thread. | ||
Static Protected Member Functions inherited from ost::Mutex | ||
| static void | setDebug (bool mode) | |
| Enable or disable deadlock debugging. | ||
Static Protected Member Functions inherited from ost::File | ||
| static const char * | getExtension (const char *path) | |
| static const char * | getFilename (const char *path) | |
| static char * | getFilename (const char *path, char *buffer, size_t size=64) | |
| static char * | getDirname (const char *path, char *buffer, size_t size=256) | |
| static char * | getRealpath (const char *path, char *buffer, size_t size=256) | |
Protected Attributes inherited from ost::RandomFile | ||
| int | fd | |
| Access | access | |
| char * | pathname | |
| struct { | ||
| unsigned count: 16 | ||
| bool thrown: 1 | ||
| bool initial: 1 | ||
| bool immediate: 1 | ||
| bool temp: 1 | ||
| } | flags | |
Related Symbols inherited from ost::RandomFile | ||
| bool __EXPORT | isDir (const char *path) | |
| bool __EXPORT | isFile (const char *path) | |
| bool __EXPORT | isDevice (const char *path) | |
| bool __EXPORT | canAccess (const char *path) | |
| bool __EXPORT | canModify (const char *path) | |
| time_t __EXPORT | lastModified (const char *path) | |
| time_t __EXPORT | lastAccessed (const char *path) | |
This class defines a database I/O file service that can be shared by multiple processes.
Each thread should access a dup of the database object, and mutex locks can be used to preserve transaction integrety if multiple threads are used.
SharedFile is used when a database may be shared between multiple processes. SharedFile automatically applies low level byte-range "file locks", and provides an interface to fetch and release byte-range locked portions of a file.
This class defines a database I/O file service that can be shared by multiple processes.
| ost::SharedFile::SharedFile | ( | const char * | path | ) |
Open or create a new database file.
You should also use Initial.
| path | pathname of database to open. |
| ost::SharedFile::SharedFile | ( | const SharedFile & | file | ) |
Create a shared file as a duplicate of an existing shared file.
| file | original file. |
|
virtual |
Close and finish a database file.
| Error ost::SharedFile::append | ( | char * | address = NULL, |
| ccxx_size_t | length = 0 ) |
Add new data to the end of the file.
Locks file during append.
| address | address to use, or NULL if same as last I/O. |
| length | length to use, or 0 if same as last I/O. |
| Error ost::SharedFile::clear | ( | ccxx_size_t | length = 0, |
| off_t | pos = -1 ) |
Clear a lock held from a previous fetch operation without updating.
| length | length to use, or 0 if same as last I/O. |
| pos | file position to use or -1 if same as last I/O. |
| Error ost::SharedFile::fetch | ( | char * | address = NULL, |
| ccxx_size_t | length = 0, | ||
| off_t | position = -1 ) |
Lock and Fetch a portion of the file into physical memory.
This can use state information to fetch the current record multiple times.
| address | address to use, or NULL if same as last I/O. |
| length | length to use, or 0 if same as last I/O. |
| position | file position to use -1 if same as last I/O. |
| off_t ost::SharedFile::getPosition | ( | void | ) |
Fetch the current file position marker for this thread.
| bool ost::SharedFile::operator++ | ( | void | ) |
| bool ost::SharedFile::operator-- | ( | void | ) |
|
inlinevirtual |
Restart an existing database; close and re-open.
Reimplemented from ost::RandomFile.
| Error ost::SharedFile::update | ( | char * | address = NULL, |
| ccxx_size_t | length = 0, | ||
| off_t | position = -1 ) |
Update a portion of a file from physical memory.
This can use state information to commit the last read record. The current lock is also cleared.
| address | address to use, or NULL if same as last I/O. |
| length | length to use, or 0 if same as last I/O. |
| position | file position to use or -1 if same as last I/O. |