php_stream_mmap.h

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/*
  +----------------------------------------------------------------------+
  | Copyright (c) The PHP Group                                          |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | https://www.php.net/license/3_01.txt                                 |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: Wez Furlong <wez@thebrainroom.com>                           |
  +----------------------------------------------------------------------+
*/
 
/* Memory Mapping interface for streams.
 * The intention is to provide a uniform interface over the most common
 * operations that are used within PHP itself, rather than a complete
 * API for all memory mapping needs.
 *
 * ATM, we support only mmap(), but win32 memory mapping support will
 * follow soon.
 * */
 
typedef enum {
    /* Does the stream support mmap ? */
    PHP_STREAM_MMAP_SUPPORTED,
    /* Request a range and offset to be mapped;
     * while mapped, you MUST NOT use any read/write functions
     * on the stream (win9x compatibility) */
    PHP_STREAM_MMAP_MAP_RANGE,
    /* Unmap the last range that was mapped for the stream */
    PHP_STREAM_MMAP_UNMAP
} php_stream_mmap_operation_t;
 
typedef enum {
    PHP_STREAM_MAP_MODE_READONLY,
    PHP_STREAM_MAP_MODE_READWRITE,
    PHP_STREAM_MAP_MODE_SHARED_READONLY,
    PHP_STREAM_MAP_MODE_SHARED_READWRITE
} php_stream_mmap_access_t;
 
typedef struct {
    /* requested offset and length.
     * If length is 0, the whole file is mapped */
    size_t offset;
    size_t length;
 
    php_stream_mmap_access_t mode;
 
    /* returned mapped address */
    char *mapped;
 
} php_stream_mmap_range;
 
#define PHP_STREAM_MMAP_ALL 0
 
#define PHP_STREAM_MMAP_MAX (512 * 1024 * 1024)
 
#define php_stream_mmap_supported(stream)   (_php_stream_set_option((stream), PHP_STREAM_OPTION_MMAP_API, PHP_STREAM_MMAP_SUPPORTED, NULL) == 0 ? 1 : 0)
 
/* Returns 1 if the stream in its current state can be memory mapped,
 * 0 otherwise */
#define php_stream_mmap_possible(stream)            (!php_stream_is_filtered((stream)) && php_stream_mmap_supported((stream)))
 
BEGIN_EXTERN_C()
PHPAPI char *_php_stream_mmap_range(php_stream *stream, size_t offset, size_t length, php_stream_mmap_access_t mode, size_t *mapped_len);
#define php_stream_mmap_range(stream, offset, length, mode, mapped_len) _php_stream_mmap_range((stream), (offset), (length), (mode), (mapped_len))
 
/* un-maps the last mapped range */
PHPAPI int _php_stream_mmap_unmap(php_stream *stream);
#define php_stream_mmap_unmap(stream)               _php_stream_mmap_unmap((stream))
 
PHPAPI int _php_stream_mmap_unmap_ex(php_stream *stream, zend_off_t readden);
#define php_stream_mmap_unmap_ex(stream, readden)           _php_stream_mmap_unmap_ex((stream), (readden))
END_EXTERN_C()