ucommon
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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 | |
Error | append (char *address=((void *) 0), ccxx_size_t length=0) |
Add new data to the end of the file. | |
Error | clear (ccxx_size_t length=0, off_t pos=-1) |
Clear a lock held from a previous fetch operation without updating. | |
Error | fetch (char *address=((void *) 0), ccxx_size_t length=0, off_t position=-1) |
Lock and Fetch a portion of the file into physical memory. | |
off_t | getPosition (void) |
Fetch the current file position marker for this thread. | |
bool | operator++ (void) |
bool | operator-- (void) |
Error | restart (void) |
Restart an existing database; close and re-open. | |
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. | |
Error | update (char *address=((void *) 0), ccxx_size_t length=0, off_t position=-1) |
Update a portion of a file from physical memory. | |
virtual | ~SharedFile () |
Close and finish a database file. | |
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off_t | getCapacity (void) |
Get current file capacity. | |
Error | getErrorNumber (void) |
Return current error id. | |
char * | getErrorString (void) |
Return current error string. | |
bool | initial (void) |
This method should be called right after a RandomFile derived object has been created. | |
bool | operator! (void) |
virtual | ~RandomFile () |
Destroy a random access file or it's derived class. | |
Additional Inherited Members | |
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enum | Access { accessReadOnly = 00, accessWriteOnly = 01, accessReadWrite = 02 } |
typedef enum Access | Access |
enum | Attr { attrInvalid = 0, attrPrivate = 0400 | 0200, attrGroup = attrPrivate | ( 0400 >> 3) | ( 0200 >> 3), attrPublic = attrGroup | ( ( 0400 >> 3) >> 3) | ( ( 0200 >> 3) >> 3) } |
typedef enum Attr | Attr |
enum | Complete { completionImmediate, completionDelayed, completionDeferred } |
typedef enum Complete | Complete |
enum | Error { errSuccess = 0, errNotOpened, errMapFailed, errInitFailed, errOpenDenied, errOpenFailed, errOpenInUse, errReadInterrupted, errReadIncomplete, errReadFailure, errWriteInterrupted, errWriteIncomplete, errWriteFailure, errLockFailure, errExtended } |
typedef enum Error | Error |
enum | Mapping { mappedRead = accessReadOnly, mappedWrite = accessWriteOnly, mappedReadWrite = accessReadWrite } |
typedef enum Mapping | Mapping |
enum | Open { openReadOnly = 00, openWriteOnly = 01, openReadWrite = 02, openAppend = 01 | 02000, openSync = 02 | 04010000, openTruncate = 02 | 01000 } |
typedef enum Open | Open |
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static char * | getDirname (const char *path, char *buffer, size_t size=4096) |
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=255) |
static char * | getRealpath (const char *path, char *buffer, size_t size=4096) |
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typedef struct ost::File::_fcb | fcb_t |
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Error | error (Error errid, char *errstr=((void *) 0)) |
Post an error event. | |
Error | error (char *err) |
Post an extended string error message. | |
void | final (void) |
Close the file. | |
virtual Attr | initialize (void) |
This method is used to initialize a newly created file as indicated by the "initial" flag. | |
RandomFile (const char *name=((void *) 0)) | |
Create an unopened random access file. | |
RandomFile (const RandomFile &rf) | |
Default copy constructor. | |
Error | setCompletion (Complete mode) |
Used to set file completion modes. | |
void | setError (bool enable) |
Used to enable or disable throwing of exceptions on errors. | |
void | setTemporary (bool enable) |
Used to set the temporary attribute for the file. | |
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Access | access |
int | fd |
struct { | |
unsigned count: 16 | |
bool immediate: 1 | |
bool initial: 1 | |
bool temp: 1 | |
bool thrown: 1 | |
} | flags |
char * | pathname |
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bool | canAccess (const char *path) |
bool | canModify (const char *path) |
bool | isDevice (const char *path) |
bool | isDir (const char *path) |
bool | isFile (const char *path) |
time_t | lastAccessed (const char *path) |
time_t | lastModified (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.
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. |
Error ost::SharedFile::append | ( | char * | address = ((void *) 0) , |
ccxx_size_t | length = 0 |
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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 |
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) |
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 = ((void *) 0) , |
ccxx_size_t | length = 0 , |
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off_t | position = -1 |
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) |
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.
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inlinevirtual |
Restart an existing database; close and re-open.
Reimplemented from ost::RandomFile.
Error ost::SharedFile::update | ( | char * | address = ((void *) 0) , |
ccxx_size_t | length = 0 , |
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off_t | position = -1 |
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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. |