Andrew's git - gitweb.git/blob

   1#ifndef PKTLINE_H
   2#define PKTLINE_H
   3
   4#include "git-compat-util.h"
   5#include "strbuf.h"
   6
   7/*
   8 * Write a packetized stream, where each line is preceded by
   9 * its length (including the header) as a 4-byte hex number.
  10 * A length of 'zero' means end of stream (and a length of 1-3
  11 * would be an error).
  12 *
  13 * This is all pretty stupid, but we use this packetized line
  14 * format to make a streaming format possible without ever
  15 * over-running the read buffers. That way we'll never read
  16 * into what might be the pack data (which should go to another
  17 * process entirely).
  18 *
  19 * The writing side could use stdio, but since the reading
  20 * side can't, we stay with pure read/write interfaces.
  21 */
  22void packet_flush(int fd);
  23void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
  24void packet_buf_flush(struct strbuf *buf);
  25void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
  26
  27/*
  28 * Read a packetized line from the descriptor into the buffer, which must be at
  29 * least size bytes long. The return value specifies the number of bytes read
  30 * into the buffer.
  31 *
  32 * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any
  33 * of the following conditions:
  34 *
  35 *   1. Read error from descriptor.
  36 *
  37 *   2. Protocol error from the remote (e.g., bogus length characters).
  38 *
  39 *   3. Receiving a packet larger than "size" bytes.
  40 *
  41 *   4. Truncated output from the remote (e.g., we expected a packet but got
  42 *      EOF, or we got a partial packet followed by EOF).
  43 *
  44 * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on
  45 * condition 4 (truncated input), but instead return -1. However, we will still
  46 * die for the other 3 conditions.
  47 *
  48 * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if
  49 * present) is removed from the buffer before returning.
  50 */
  51#define PACKET_READ_GENTLE_ON_EOF (1u<<0)
  52#define PACKET_READ_CHOMP_NEWLINE (1u<<1)
  53int packet_read(int fd, char *buffer, unsigned size, int options);
  54
  55/*
  56 * Convenience wrapper for packet_read that is not gentle, and sets the
  57 * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
  58 * and otherwise points to a static buffer (that may be overwritten by
  59 * subsequent calls). If the size parameter is not NULL, the length of the
  60 * packet is written to it.
  61 */
  62char *packet_read_line(int fd, int *size);
  63
  64
  65#define DEFAULT_PACKET_MAX 1000
  66#define LARGE_PACKET_MAX 65520
  67extern char packet_buffer[LARGE_PACKET_MAX];
  68
  69int packet_get_line(struct strbuf *out, char **src_buf, size_t *src_len);
  70
  71#endif