pkt-line: provide a generic reading function with options
[git/git.git] / pkt-line.h
CommitLineData
f3a3214e
LT
1#ifndef PKTLINE_H
2#define PKTLINE_H
3
07d68930 4#include "git-compat-util.h"
f5615d24 5#include "strbuf.h"
07d68930 6
f3a3214e 7/*
e1485428
JK
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.
f3a3214e
LT
21 */
22void packet_flush(int fd);
4ec99bf0 23void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
f5615d24
SP
24void packet_buf_flush(struct strbuf *buf);
25void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
f3a3214e 26
03809429
JK
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#define PACKET_READ_GENTLE_ON_EOF (1u<<0)
49int packet_read(int fd, char *buffer, unsigned size, int options);
50
51/* Historical convenience wrapper for packet_read that sets no options */
f3a3214e 52int packet_read_line(int fd, char *buffer, unsigned size);
03809429 53
f5615d24 54int packet_get_line(struct strbuf *out, char **src_buf, size_t *src_len);
f3a3214e
LT
55
56#endif