prio.h

Netscape NSPR库源码

 *     The dynamic memory pointed to by the argument fd is freed.
 **************************************************************************
 */

NSPR_API(PRStatus)    PR_Close(PRFileDesc *fd);

/*
 **************************************************************************
 * FUNCTION: PR_Read
 * DESCRIPTION:
 *     Read bytes from a file or socket.
 *     The operation will block until either an end of stream indication is
 *     encountered, some positive number of bytes are transferred, or there
 *     is an error. No more than 'amount' bytes will be transferred.
 * INPUTS:
 *     PRFileDesc *fd
 *         pointer to the PRFileDesc object for the file or socket
 *     void *buf
 *         pointer to a buffer to hold the data read in.
 *     PRInt32 amount
 *         the size of 'buf' (in bytes)
 * OUTPUTS:
 * RETURN:
 *     PRInt32
 *         a positive number indicates the number of bytes actually read in.
 *         0 means end of file is reached or the network connection is closed.
 *         -1 indicates a failure. The reason for the failure is obtained
 *         by calling PR_GetError().
 * SIDE EFFECTS:
 *     data is written into the buffer pointed to by 'buf'.
 * RESTRICTIONS:
 *     None.
 * MEMORY:
 *     N/A
 * ALGORITHM:
 *     N/A
 **************************************************************************
 */

NSPR_API(PRInt32) PR_Read(PRFileDesc *fd, void *buf, PRInt32 amount);

/*
 ***************************************************************************
 * FUNCTION: PR_Write
 * DESCRIPTION:
 *     Write a specified number of bytes to a file or socket.  The thread
 *     invoking this function blocks until all the data is written.
 * INPUTS:
 *     PRFileDesc *fd
 *         pointer to a PRFileDesc object that refers to a file or socket
 *     const void *buf
 *         pointer to the buffer holding the data
 *     PRInt32 amount
 *         amount of data in bytes to be written from the buffer
 * OUTPUTS:
 *     None.
 * RETURN: PRInt32
 *     A positive number indicates the number of bytes successfully written.
 *     A -1 is an indication that the operation failed. The reason
 *     for the failure is obtained by calling PR_GetError().
 ***************************************************************************
 */

NSPR_API(PRInt32) PR_Write(PRFileDesc *fd,const void *buf,PRInt32 amount);

/*
 ***************************************************************************
 * FUNCTION: PR_Writev
 * DESCRIPTION:
 *     Write data to a socket.  The data is organized in a PRIOVec array. The
 *     operation will block until all the data is written or the operation
 *     fails.
 * INPUTS:
 *     PRFileDesc *fd
 *         Pointer that points to a PRFileDesc object for a socket.
 *     const PRIOVec *iov
 *         An array of PRIOVec.  PRIOVec is a struct with the following
 *         two fields:
 *             char *iov_base;
 *             int iov_len;
 *     PRInt32 iov_size
 *         Number of elements in the iov array. The value of this
 *         argument must not be greater than PR_MAX_IOVECTOR_SIZE.
 *         If it is, the method will fail (PR_BUFFER_OVERFLOW_ERROR).
 *     PRIntervalTime timeout
 *       Time limit for completion of the entire write operation.
 * OUTPUTS:
 *     None
 * RETURN:
 *     A positive number indicates the number of bytes successfully written.
 *     A -1 is an indication that the operation failed. The reason
 *     for the failure is obtained by calling PR_GetError().
 ***************************************************************************
 */

#define PR_MAX_IOVECTOR_SIZE 16   /* 'iov_size' must be <= */

NSPR_API(PRInt32) PR_Writev(
    PRFileDesc *fd, const PRIOVec *iov, PRInt32 iov_size,
    PRIntervalTime timeout);

/*
 ***************************************************************************
 * FUNCTION: PR_Delete
 * DESCRIPTION:
 *     Delete a file from the filesystem. The operation may fail if the
 *     file is open.
 * INPUTS:
 *     const char *name
 *         Path name of the file to be deleted.
 * OUTPUTS:
 *     None.
 * RETURN: PRStatus
 *     The function returns PR_SUCCESS if the file is successfully
 *     deleted, otherwise it returns PR_FAILURE.
 ***************************************************************************
 */

NSPR_API(PRStatus) PR_Delete(const char *name);

/**************************************************************************/

typedef enum PRFileType
{
    PR_FILE_FILE = 1,
    PR_FILE_DIRECTORY = 2,
    PR_FILE_OTHER = 3
} PRFileType;

struct PRFileInfo {
    PRFileType type;        /* Type of file */
    PROffset32 size;        /* Size, in bytes, of file's contents */
    PRTime creationTime;    /* Creation time per definition of PRTime */
    PRTime modifyTime;      /* Last modification time per definition of PRTime */
};

struct PRFileInfo64 {
    PRFileType type;        /* Type of file */
    PROffset64 size;        /* Size, in bytes, of file's contents */
    PRTime creationTime;    /* Creation time per definition of PRTime */
    PRTime modifyTime;      /* Last modification time per definition of PRTime */
};

/****************************************************************************
 * FUNCTION: PR_GetFileInfo, PR_GetFileInfo64
 * DESCRIPTION:
 *     Get the information about the file with the given path name. This is
 *     applicable only to NSFileDesc describing 'file' types (see
 * INPUTS:
 *     const char *fn
 *         path name of the file
 * OUTPUTS:
 *     PRFileInfo *info
 *         Information about the given file is written into the file
 *         information object pointer to by 'info'.
 * RETURN: PRStatus
 *     PR_GetFileInfo returns PR_SUCCESS if file information is successfully
 *     obtained, otherwise it returns PR_FAILURE.
 ***************************************************************************
 */

NSPR_API(PRStatus) PR_GetFileInfo(const char *fn, PRFileInfo *info);
NSPR_API(PRStatus) PR_GetFileInfo64(const char *fn, PRFileInfo64 *info);

/*
 **************************************************************************
 * FUNCTION: PR_GetOpenFileInfo, PR_GetOpenFileInfo64
 * DESCRIPTION:
 *     Get information about an open file referred to by the
 *     given PRFileDesc object.
 * INPUTS:
 *     const PRFileDesc *fd
 *          A reference to a valid, open file.
 * OUTPUTS:
 *     Same as PR_GetFileInfo, PR_GetFileInfo64
 * RETURN: PRStatus
 *     PR_GetFileInfo returns PR_SUCCESS if file information is successfully
 *     obtained, otherwise it returns PR_FAILURE.
 ***************************************************************************
 */

NSPR_API(PRStatus) PR_GetOpenFileInfo(PRFileDesc *fd, PRFileInfo *info);
NSPR_API(PRStatus) PR_GetOpenFileInfo64(PRFileDesc *fd, PRFileInfo64 *info);

/*
 **************************************************************************
 * FUNCTION: PR_Rename
 * DESCRIPTION:
 *     Rename a file from the old name 'from' to the new name 'to'.
 * INPUTS:
 *     const char *from
 *         The old name of the file to be renamed.
 *     const char *to
 *         The new name of the file.
 * OUTPUTS:
 *     None.
 * RETURN: PRStatus
 **************************************************************************
 */

NSPR_API(PRStatus)    PR_Rename(const char *from, const char *to);

/*
 *************************************************************************
 * FUNCTION: PR_Access
 * DESCRIPTION:
 *     Determine accessibility of a file.
 * INPUTS:
 *     const char *name
 *         path name of the file
 *     PRAccessHow how
 *         specifies which access permission to check for.
 *         It can be one of the following values:
 *             PR_ACCESS_READ_OK       Test for read permission
 *             PR_ACCESS_WRITE_OK      Test for write permission
 *             PR_ACCESS_EXISTS        Check existence of file
 * OUTPUTS:
 *     None.
 * RETURN: PRStatus
 *     PR_SUCCESS is returned if the requested access is permitted.
 *     Otherwise, PR_FAILURE is returned. Additional information
 *     regarding the reason for the failure may be retrieved from
 *     PR_GetError().
 *************************************************************************
 */

typedef enum PRAccessHow {
    PR_ACCESS_EXISTS = 1,
    PR_ACCESS_WRITE_OK = 2,
    PR_ACCESS_READ_OK = 3
} PRAccessHow;

NSPR_API(PRStatus) PR_Access(const char *name, PRAccessHow how);

/*
 *************************************************************************
 * FUNCTION: PR_Seek, PR_Seek64
 * DESCRIPTION:
 *     Moves read-write file offset
 * INPUTS:
 *     PRFileDesc *fd
 *         Pointer to a PRFileDesc object.
 *     PROffset32, PROffset64 offset
 *         Specifies a value, in bytes, that is used in conjunction
 *         with the 'whence' parameter to set the file pointer.  A
 *         negative value causes seeking in the reverse direction.
 *     PRSeekWhence whence
 *         Specifies how to interpret the 'offset' parameter in setting
 *         the file pointer associated with the 'fd' parameter.
 *         Values for the 'whence' parameter are:
 *             PR_SEEK_SET  Sets the file pointer to the value of the
 *                          'offset' parameter
 *             PR_SEEK_CUR  Sets the file pointer to its current location
 *                          plus the value of the offset parameter.
 *             PR_SEEK_END  Sets the file pointer to the size of the
 *                          file plus the value of the offset parameter.
 * OUTPUTS:
 *     None.
 * RETURN: PROffset32, PROffset64
 *     Upon successful completion, the resulting pointer location,
 *     measured in bytes from the beginning of the file, is returned.
 *     If the PR_Seek() function fails, the file offset remains
 *     unchanged, and the returned value is -1. The error code can
 *     then be retrieved via PR_GetError().
 *************************************************************************
 */

NSPR_API(PROffset32) PR_Seek(PRFileDesc *fd, PROffset32 offset, PRSeekWhence whence);
NSPR_API(PROffset64) PR_Seek64(PRFileDesc *fd, PROffset64 offset, PRSeekWhence whence);

/*
 ************************************************************************
 * FUNCTION: PR_Available
 * DESCRIPTION:
 *     Determine the amount of data in bytes available for reading
 *     in the given file or socket.
 * INPUTS:
 *     PRFileDesc *fd
 *         Pointer to a PRFileDesc object that refers to a file or
 *         socket.
 * OUTPUTS:
 *     None
 * RETURN: PRInt32, PRInt64
 *     Upon successful completion, PR_Available returns the number of
 *     bytes beyond the current read pointer that is available for
 *     reading.  Otherwise, it returns a -1 and the reason for the
 *     failure can be retrieved via PR_GetError().
 ************************************************************************
 */

NSPR_API(PRInt32) PR_Available(PRFileDesc *fd);
NSPR_API(PRInt64) PR_Available64(PRFileDesc *fd);

/*
 ************************************************************************
 * FUNCTION: PR_Sync
 * DESCRIPTION:
 *     Sync any buffered data for a fd to its backing device (disk).
 * INPUTS:
 *     PRFileDesc *fd
 *         Pointer to a PRFileDesc object that refers to a file or
 *         socket
 * OUTPUTS:
 *     None
 * RETURN: PRStatus
 *     PR_SUCCESS is returned if the requested access is permitted.
 *     Otherwise, PR_FAILURE is returned.
 ************************************************************************
 */

NSPR_API(PRStatus)	PR_Sync(PRFileDesc *fd);

/************************************************************************/

struct PRDirEntry {
    const char *name;        /* name of entry, relative to directory name */
};

#if !defined(NO_NSPR_10_SUPPORT)
#define PR_DirName(dirEntry)	(dirEntry->name)
#endif

/*
 *************************************************************************
 * FUNCTION: PR_OpenDir
 * DESCRIPTION:
 *     Open the directory by the given name
 * INPUTS:
 *     const char *name
 *         path name of the directory to be opened
 * OUTPUTS:
 *     None
 * RETURN: PRDir *
 *     If the directory is sucessfully opened, a PRDir object is