tor/src/common/buffers.h

132 lines
4.5 KiB
C

/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file buffers.h
* \brief Header file for buffers.c.
**/
#ifndef TOR_BUFFERS_H
#define TOR_BUFFERS_H
#include "compat.h"
#include "torint.h"
#include "testsupport.h"
typedef struct buf_t buf_t;
struct tor_compress_state_t;
buf_t *buf_new(void);
buf_t *buf_new_with_capacity(size_t size);
size_t buf_get_default_chunk_size(const buf_t *buf);
void buf_free_(buf_t *buf);
#define buf_free(b) FREE_AND_NULL(buf_t, buf_free_, (b))
void buf_clear(buf_t *buf);
buf_t *buf_copy(const buf_t *buf);
MOCK_DECL(size_t, buf_datalen, (const buf_t *buf));
size_t buf_allocation(const buf_t *buf);
size_t buf_slack(const buf_t *buf);
uint32_t buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now);
size_t buf_get_total_allocation(void);
int buf_read_from_socket(buf_t *buf, tor_socket_t s, size_t at_most,
int *reached_eof,
int *socket_error);
int buf_flush_to_socket(buf_t *buf, tor_socket_t s, size_t sz,
size_t *buf_flushlen);
int buf_add(buf_t *buf, const char *string, size_t string_len);
void buf_add_string(buf_t *buf, const char *string);
void buf_add_printf(buf_t *buf, const char *format, ...)
CHECK_PRINTF(2, 3);
void buf_add_vprintf(buf_t *buf, const char *format, va_list args)
CHECK_PRINTF(2, 0);
int buf_add_compress(buf_t *buf, struct tor_compress_state_t *state,
const char *data, size_t data_len, int done);
int buf_move_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen);
void buf_move_all(buf_t *buf_out, buf_t *buf_in);
void buf_peek(const buf_t *buf, char *string, size_t string_len);
void buf_drain(buf_t *buf, size_t n);
int buf_get_bytes(buf_t *buf, char *string, size_t string_len);
int buf_get_line(buf_t *buf, char *data_out, size_t *data_len);
#define PEEK_BUF_STARTSWITH_MAX 16
int buf_peek_startswith(const buf_t *buf, const char *cmd);
int buf_set_to_copy(buf_t **output,
const buf_t *input);
void buf_assert_ok(buf_t *buf);
int buf_find_string_offset(const buf_t *buf, const char *s, size_t n);
void buf_pullup(buf_t *buf, size_t bytes,
const char **head_out, size_t *len_out);
char *buf_extract(buf_t *buf, size_t *sz_out);
#ifdef BUFFERS_PRIVATE
#ifdef TOR_UNIT_TESTS
buf_t *buf_new_with_data(const char *cp, size_t sz);
#endif
size_t buf_preferred_chunk_size(size_t target);
#define DEBUG_CHUNK_ALLOC
/** A single chunk on a buffer. */
typedef struct chunk_t {
struct chunk_t *next; /**< The next chunk on the buffer. */
size_t datalen; /**< The number of bytes stored in this chunk */
size_t memlen; /**< The number of usable bytes of storage in <b>mem</b>. */
#ifdef DEBUG_CHUNK_ALLOC
size_t DBG_alloc;
#endif
char *data; /**< A pointer to the first byte of data stored in <b>mem</b>. */
uint32_t inserted_time; /**< Timestamp when this chunk was inserted. */
char mem[FLEXIBLE_ARRAY_MEMBER]; /**< The actual memory used for storage in
* this chunk. */
} chunk_t;
/** Magic value for buf_t.magic, to catch pointer errors. */
#define BUFFER_MAGIC 0xB0FFF312u
/** A resizeable buffer, optimized for reading and writing. */
struct buf_t {
uint32_t magic; /**< Magic cookie for debugging: Must be set to
* BUFFER_MAGIC. */
size_t datalen; /**< How many bytes is this buffer holding right now? */
size_t default_chunk_size; /**< Don't allocate any chunks smaller than
* this for this buffer. */
chunk_t *head; /**< First chunk in the list, or NULL for none. */
chunk_t *tail; /**< Last chunk in the list, or NULL for none. */
};
chunk_t *buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped);
/** If a read onto the end of a chunk would be smaller than this number, then
* just start a new chunk. */
#define MIN_READ_LEN 8
/** Return the number of bytes that can be written onto <b>chunk</b> without
* running out of space. */
static inline size_t
CHUNK_REMAINING_CAPACITY(const chunk_t *chunk)
{
return (chunk->mem + chunk->memlen) - (chunk->data + chunk->datalen);
}
/** Return the next character in <b>chunk</b> onto which data can be appended.
* If the chunk is full, this might be off the end of chunk->mem. */
static inline char *
CHUNK_WRITE_PTR(chunk_t *chunk)
{
return chunk->data + chunk->datalen;
}
#endif /* defined(BUFFERS_PRIVATE) */
#endif /* !defined(TOR_BUFFERS_H) */