buffer.h

Go to the documentation of this file.

/*
 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef _EVENT2_BUFFER_H_
#define _EVENT2_BUFFER_H_

#ifdef __cplusplus
extern "C" {
#endif

#include <event2/event-config.h>
#include <stdarg.h>
#ifdef _EVENT_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef _EVENT_HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#include <event2/util.h>

struct evbuffer
#ifdef _EVENT_IN_DOXYGEN
{}
#endif
;

struct evbuffer_ptr {
    ev_ssize_t pos;

    /* Do not alter the values of fields. */
    struct {
        void *chain;
        size_t pos_in_chain;
    } _internal;
};

#ifdef _EVENT_HAVE_SYS_UIO_H
#define evbuffer_iovec iovec
/* Internal use -- defined only if we are using the native struct iovec */
#define _EVBUFFER_IOVEC_IS_NATIVE
#else
struct evbuffer_iovec {
    void *iov_base;
    size_t iov_len;
};
#endif

struct evbuffer *evbuffer_new(void);
void evbuffer_free(struct evbuffer *buf);

int evbuffer_enable_locking(struct evbuffer *buf, void *lock);

void evbuffer_lock(struct evbuffer *buf);

void evbuffer_unlock(struct evbuffer *buf);


#define EVBUFFER_FLAG_DRAINS_TO_FD 1

int evbuffer_set_flags(struct evbuffer *buf, ev_uint64_t flags);
int evbuffer_clear_flags(struct evbuffer *buf, ev_uint64_t flags);

size_t evbuffer_get_length(const struct evbuffer *buf);

size_t evbuffer_get_contiguous_space(const struct evbuffer *buf);

int evbuffer_expand(struct evbuffer *buf, size_t datlen);

int
evbuffer_reserve_space(struct evbuffer *buf, ev_ssize_t size,
    struct evbuffer_iovec *vec, int n_vec);

int evbuffer_commit_space(struct evbuffer *buf,
    struct evbuffer_iovec *vec, int n_vecs);

int evbuffer_add(struct evbuffer *buf, const void *data, size_t datlen);


int evbuffer_remove(struct evbuffer *buf, void *data, size_t datlen);

ev_ssize_t evbuffer_copyout(struct evbuffer *buf, void *data_out, size_t datlen);

int evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst,
    size_t datlen);

enum evbuffer_eol_style {
    EVBUFFER_EOL_ANY,
    EVBUFFER_EOL_CRLF,
    EVBUFFER_EOL_CRLF_STRICT,
    EVBUFFER_EOL_LF
};

char *evbuffer_readln(struct evbuffer *buffer, size_t *n_read_out,
    enum evbuffer_eol_style eol_style);

int evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf);

typedef void (*evbuffer_ref_cleanup_cb)(const void *data,
    size_t datalen, void *extra);

int evbuffer_add_reference(struct evbuffer *outbuf,
    const void *data, size_t datlen,
    evbuffer_ref_cleanup_cb cleanupfn, void *cleanupfn_arg);

int evbuffer_add_file(struct evbuffer *outbuf, int fd, ev_off_t offset,
    ev_off_t length);

int evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...)
#ifdef __GNUC__
  __attribute__((format(printf, 2, 3)))
#endif
;

int evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
#ifdef __GNUC__
    __attribute__((format(printf, 2, 0)))
#endif
;


int evbuffer_drain(struct evbuffer *buf, size_t len);


int evbuffer_write(struct evbuffer *buffer, evutil_socket_t fd);

int evbuffer_write_atmost(struct evbuffer *buffer, evutil_socket_t fd,
                          ev_ssize_t howmuch);

int evbuffer_read(struct evbuffer *buffer, evutil_socket_t fd, int howmuch);

struct evbuffer_ptr evbuffer_search(struct evbuffer *buffer, const char *what, size_t len, const struct evbuffer_ptr *start);

struct evbuffer_ptr evbuffer_search_range(struct evbuffer *buffer, const char *what, size_t len, const struct evbuffer_ptr *start, const struct evbuffer_ptr *end);

enum evbuffer_ptr_how {
    EVBUFFER_PTR_SET,
    EVBUFFER_PTR_ADD
};

int
evbuffer_ptr_set(struct evbuffer *buffer, struct evbuffer_ptr *ptr,
    size_t position, enum evbuffer_ptr_how how);

struct evbuffer_ptr evbuffer_search_eol(struct evbuffer *buffer,
    struct evbuffer_ptr *start, size_t *eol_len_out,
    enum evbuffer_eol_style eol_style);

int evbuffer_peek(struct evbuffer *buffer, ev_ssize_t len,
    struct evbuffer_ptr *start_at,
    struct evbuffer_iovec *vec_out, int n_vec);


struct evbuffer_cb_info {
    size_t orig_size;
    size_t n_added;
    size_t n_deleted;
};

typedef void (*evbuffer_cb_func)(struct evbuffer *buffer, const struct evbuffer_cb_info *info, void *arg);

struct evbuffer_cb_entry;
struct evbuffer_cb_entry *evbuffer_add_cb(struct evbuffer *buffer, evbuffer_cb_func cb, void *cbarg);

int evbuffer_remove_cb_entry(struct evbuffer *buffer,
                 struct evbuffer_cb_entry *ent);

int evbuffer_remove_cb(struct evbuffer *buffer, evbuffer_cb_func cb, void *cbarg);

#define EVBUFFER_CB_ENABLED 1

int evbuffer_cb_set_flags(struct evbuffer *buffer,
              struct evbuffer_cb_entry *cb, ev_uint32_t flags);

int evbuffer_cb_clear_flags(struct evbuffer *buffer,
              struct evbuffer_cb_entry *cb, ev_uint32_t flags);

#if 0

void evbuffer_cb_suspend(struct evbuffer *buffer, struct evbuffer_cb_entry *cb);
void evbuffer_cb_unsuspend(struct evbuffer *buffer, struct evbuffer_cb_entry *cb);
#endif

unsigned char *evbuffer_pullup(struct evbuffer *buf, ev_ssize_t size);

int evbuffer_prepend(struct evbuffer *buf, const void *data, size_t size);

int evbuffer_prepend_buffer(struct evbuffer *dst, struct evbuffer* src);

int evbuffer_freeze(struct evbuffer *buf, int at_front);
int evbuffer_unfreeze(struct evbuffer *buf, int at_front);

struct event_base;
int evbuffer_defer_callbacks(struct evbuffer *buffer, struct event_base *base);

#ifdef __cplusplus
}
#endif

#endif /* _EVENT2_BUFFER_H_ */