evbuffer-internal.h

/*
 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
 * 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 EVBUFFER_INTERNAL_H_INCLUDED_
#define EVBUFFER_INTERNAL_H_INCLUDED_
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include "event2/event-config.h"
#include "evconfig-private.h"
#include "event2/util.h"
#include "event2/event_struct.h"
#include "util-internal.h"
#include "defer-internal.h"
 
/* Experimental cb flag: "never deferred."  Implementation note:
 * these callbacks may get an inaccurate view of n_del/n_added in their
 * arguments. */
#define EVBUFFER_CB_NODEFER 2
 
#ifdef _WIN32
#include <winsock2.h>
#endif
#include <sys/queue.h>
 
/* Minimum allocation for a chain.  We define this so that we're burning no
 * more than 5% of each allocation on overhead.  It would be nice to lose even
 * less space, though. */
#if EVENT__SIZEOF_VOID_P < 8
#define MIN_BUFFER_SIZE 512
#else
#define MIN_BUFFER_SIZE 1024
#endif
 
struct evbuffer_cb_entry {
    LIST_ENTRY(evbuffer_cb_entry) next;
    union {
        evbuffer_cb_func cb_func;
        evbuffer_cb cb_obsolete;
    } cb;
    void *cbarg;
    ev_uint32_t flags;
};
 
struct bufferevent;
struct evbuffer_chain;
struct evbuffer {
    struct evbuffer_chain *first;
    struct evbuffer_chain *last;
 
    struct evbuffer_chain **last_with_datap;
 
    size_t total_len;
 
    size_t n_add_for_cb;
    size_t n_del_for_cb;
 
#ifndef EVENT__DISABLE_THREAD_SUPPORT
    void *lock;
#endif
    unsigned own_lock : 1;
    unsigned freeze_start : 1;
    unsigned freeze_end : 1;
    unsigned deferred_cbs : 1;
#ifdef _WIN32
    unsigned is_overlapped : 1;
#endif
    ev_uint32_t flags;
 
    struct event_base *cb_queue;
 
    int refcnt;
 
    struct event_callback deferred;
 
    LIST_HEAD(evbuffer_cb_queue, evbuffer_cb_entry) callbacks;
 
    struct bufferevent *parent;
};
 
#if EVENT__SIZEOF_OFF_T < EVENT__SIZEOF_SIZE_T
typedef ev_ssize_t ev_misalign_t;
#define EVBUFFER_CHAIN_MAX ((size_t)EV_SSIZE_MAX)
#else
typedef ev_off_t ev_misalign_t;
#if EVENT__SIZEOF_OFF_T > EVENT__SIZEOF_SIZE_T
#define EVBUFFER_CHAIN_MAX EV_SIZE_MAX
#else
#define EVBUFFER_CHAIN_MAX ((size_t)EV_SSIZE_MAX)
#endif
#endif
 
struct evbuffer_chain {
    struct evbuffer_chain *next;
 
    size_t buffer_len;
 
    ev_misalign_t misalign;
 
    size_t off;
 
    unsigned flags;
#define EVBUFFER_FILESEGMENT    0x0001  
#define EVBUFFER_SENDFILE   0x0002  
#define EVBUFFER_REFERENCE  0x0004  
#define EVBUFFER_IMMUTABLE  0x0008  
#define EVBUFFER_MEM_PINNED_R   0x0010
#define EVBUFFER_MEM_PINNED_W   0x0020
#define EVBUFFER_MEM_PINNED_ANY (EVBUFFER_MEM_PINNED_R|EVBUFFER_MEM_PINNED_W)
#define EVBUFFER_DANGLING   0x0040
#define EVBUFFER_MULTICAST  0x0080
 
    int refcnt;
 
    unsigned char *buffer;
};
 
struct evbuffer_chain_reference {
    evbuffer_ref_cleanup_cb cleanupfn;
    void *extra;
};
 
struct evbuffer_chain_file_segment {
    struct evbuffer_file_segment *segment;
#ifdef _WIN32
    HANDLE view_handle;
#endif
};
 
/* Declared in event2/buffer.h; defined here. */
struct evbuffer_file_segment {
    void *lock; 
    int refcnt; 
    unsigned flags; 
    unsigned can_sendfile : 1;
    unsigned is_mapping : 1;
 
    int fd;
    void *mapping;
#ifdef _WIN32
    HANDLE mapping_handle;
#endif
    char *contents;
    ev_off_t file_offset;
    ev_off_t mmap_offset;
    ev_off_t length;
    evbuffer_file_segment_cleanup_cb cleanup_cb;
    void *cleanup_cb_arg;
};
 
struct evbuffer_multicast_parent {
    struct evbuffer *source;
    struct evbuffer_chain *parent;
};
 
#define EVBUFFER_CHAIN_SIZE sizeof(struct evbuffer_chain)
#define EVBUFFER_CHAIN_EXTRA(t, c) (t *)((struct evbuffer_chain *)(c) + 1)
 
#define ASSERT_EVBUFFER_LOCKED(buffer)          \
    EVLOCK_ASSERT_LOCKED((buffer)->lock)
 
#define EVBUFFER_LOCK(buffer)                       \
    do {                                \
        EVLOCK_LOCK((buffer)->lock, 0);             \
    } while (0)
#define EVBUFFER_UNLOCK(buffer)                     \
    do {                                \
        EVLOCK_UNLOCK((buffer)->lock, 0);           \
    } while (0)
#define EVBUFFER_LOCK2(buffer1, buffer2)                \
    do {                                \
        EVLOCK_LOCK2((buffer1)->lock, (buffer2)->lock, 0, 0);   \
    } while (0)
#define EVBUFFER_UNLOCK2(buffer1, buffer2)              \
    do {                                \
        EVLOCK_UNLOCK2((buffer1)->lock, (buffer2)->lock, 0, 0); \
    } while (0)
 
void evbuffer_incref_(struct evbuffer *buf);
void evbuffer_incref_and_lock_(struct evbuffer *buf);
void evbuffer_chain_pin_(struct evbuffer_chain *chain, unsigned flag);
void evbuffer_chain_unpin_(struct evbuffer_chain *chain, unsigned flag);
void evbuffer_decref_and_unlock_(struct evbuffer *buffer);
 
int evbuffer_expand_fast_(struct evbuffer *, size_t, int);
 
int evbuffer_read_setup_vecs_(struct evbuffer *buf, ev_ssize_t howmuch,
    struct evbuffer_iovec *vecs, int n_vecs, struct evbuffer_chain ***chainp,
    int exact);
 
/* Helper macro: copies an evbuffer_iovec in ei to a win32 WSABUF in i. */
#define WSABUF_FROM_EVBUFFER_IOV(i,ei) do {     \
        (i)->buf = (ei)->iov_base;      \
        (i)->len = (unsigned long)(ei)->iov_len;    \
    } while (0)
/* XXXX the cast above is safe for now, but not if we allow mmaps on win64.
 * See note in buffer_iocp's launch_write function */
 
void evbuffer_set_parent_(struct evbuffer *buf, struct bufferevent *bev);
 
void evbuffer_invoke_callbacks_(struct evbuffer *buf);
 
 
int evbuffer_get_callbacks_(struct evbuffer *buffer,
    struct event_callback **cbs,
    int max_cbs);
 
#ifdef __cplusplus
}
#endif
 
#endif /* EVBUFFER_INTERNAL_H_INCLUDED_ */