/* +----------------------------------------------------------------------+ | 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> | | With suggestions from: | | Moriyoshi Koizumi <moriyoshi@at.wakwak.com> | | Sara Golemon <pollita@php.net> | +----------------------------------------------------------------------+ */ /* The filter API works on the principle of "Bucket-Brigades". This is * partially inspired by the Apache 2 method of doing things, although * it is intentionally a light-weight implementation. * * Each stream can have a chain of filters for reading and another for writing. * * When data is written to the stream, it is placed into a bucket and placed at * the start of the input brigade. * * The first filter in the chain is invoked on the brigade and (depending on * it's return value), the next filter is invoked and so on. * */ #define PHP_STREAM_FILTER_READ 0x0001 #define PHP_STREAM_FILTER_WRITE 0x0002 #define PHP_STREAM_FILTER_ALL (PHP_STREAM_FILTER_READ | PHP_STREAM_FILTER_WRITE) typedef struct _php_stream_bucket php_stream_bucket; typedef struct _php_stream_bucket_brigade php_stream_bucket_brigade; struct _php_stream_bucket { php_stream_bucket *next, *prev; php_stream_bucket_brigade *brigade; char *buf; size_t buflen; /* if non-zero, buf should be pefreed when the bucket is destroyed */ uint8_t own_buf; uint8_t is_persistent; /* destroy this struct when refcount falls to zero */ int refcount; }; struct _php_stream_bucket_brigade { php_stream_bucket *head, *tail; }; typedef enum { PSFS_ERR_FATAL, /* error in data stream */ PSFS_FEED_ME, /* filter needs more data; stop processing chain until more is available */ PSFS_PASS_ON /* filter generated output buckets; pass them on to next in chain */ } php_stream_filter_status_t; /* Buckets API. */ BEGIN_EXTERN_C() PHPAPI php_stream_bucket *php_stream_bucket_new(php_stream *stream, char *buf, size_t buflen, uint8_t own_buf, uint8_t buf_persistent); PHPAPI int php_stream_bucket_split(php_stream_bucket *in, php_stream_bucket **left, php_stream_bucket **right, size_t length); PHPAPI void php_stream_bucket_delref(php_stream_bucket *bucket); #define php_stream_bucket_addref(bucket) (bucket)->refcount++ PHPAPI void php_stream_bucket_prepend(php_stream_bucket_brigade *brigade, php_stream_bucket *bucket); PHPAPI void php_stream_bucket_append(php_stream_bucket_brigade *brigade, php_stream_bucket *bucket); PHPAPI void php_stream_bucket_unlink(php_stream_bucket *bucket); PHPAPI php_stream_bucket *php_stream_bucket_make_writeable(php_stream_bucket *bucket); END_EXTERN_C() #define PSFS_FLAG_NORMAL 0 /* regular read/write */ #define PSFS_FLAG_FLUSH_INC 1 /* an incremental flush */ #define PSFS_FLAG_FLUSH_CLOSE 2 /* final flush prior to closing */ typedef struct _php_stream_filter_ops { php_stream_filter_status_t (*filter)( php_stream *stream, php_stream_filter *thisfilter, php_stream_bucket_brigade *buckets_in, php_stream_bucket_brigade *buckets_out, size_t *bytes_consumed, int flags ); void (*dtor)(php_stream_filter *thisfilter); const char *label; } php_stream_filter_ops; typedef struct _php_stream_filter_chain { php_stream_filter *head, *tail; /* Owning stream */ php_stream *stream; } php_stream_filter_chain; struct _php_stream_filter { const php_stream_filter_ops *fops; zval abstract; /* for use by filter implementation */ php_stream_filter *next; php_stream_filter *prev; int is_persistent; /* link into stream and chain */ php_stream_filter_chain *chain; /* buffered buckets */ php_stream_bucket_brigade buffer; /* filters are auto_registered when they're applied */ zend_resource *res; }; /* stack filter onto a stream */ BEGIN_EXTERN_C() PHPAPI void _php_stream_filter_prepend(php_stream_filter_chain *chain, php_stream_filter *filter); PHPAPI int php_stream_filter_prepend_ex(php_stream_filter_chain *chain, php_stream_filter *filter); PHPAPI void _php_stream_filter_append(php_stream_filter_chain *chain, php_stream_filter *filter); PHPAPI int php_stream_filter_append_ex(php_stream_filter_chain *chain, php_stream_filter *filter); PHPAPI int _php_stream_filter_flush(php_stream_filter *filter, int finish); PHPAPI php_stream_filter *php_stream_filter_remove(php_stream_filter *filter, int call_dtor); PHPAPI void php_stream_filter_free(php_stream_filter *filter); PHPAPI php_stream_filter *_php_stream_filter_alloc(const php_stream_filter_ops *fops, void *abstract, uint8_t persistent STREAMS_DC); END_EXTERN_C() #define php_stream_filter_alloc(fops, thisptr, persistent) _php_stream_filter_alloc((fops), (thisptr), (persistent) STREAMS_CC) #define php_stream_filter_alloc_rel(fops, thisptr, persistent) _php_stream_filter_alloc((fops), (thisptr), (persistent) STREAMS_REL_CC) #define php_stream_filter_prepend(chain, filter) _php_stream_filter_prepend((chain), (filter)) #define php_stream_filter_append(chain, filter) _php_stream_filter_append((chain), (filter)) #define php_stream_filter_flush(filter, finish) _php_stream_filter_flush((filter), (finish)) #define php_stream_is_filtered(stream) ((stream)->readfilters.head || (stream)->writefilters.head) typedef struct _php_stream_filter_factory { php_stream_filter *(*create_filter)(const char *filtername, zval *filterparams, uint8_t persistent); } php_stream_filter_factory; BEGIN_EXTERN_C() PHPAPI int php_stream_filter_register_factory(const char *filterpattern, const php_stream_filter_factory *factory); PHPAPI int php_stream_filter_unregister_factory(const char *filterpattern); PHPAPI int php_stream_filter_register_factory_volatile(zend_string *filterpattern, const php_stream_filter_factory *factory); PHPAPI php_stream_filter *php_stream_filter_create(const char *filtername, zval *filterparams, uint8_t persistent); END_EXTERN_C()