Merge tag 'v2.14.1'
[git/raj.git] / pkt-line.h
blob450183b6496fce4ec3077322f61623152c87cf07
1 #ifndef PKTLINE_H
2 #define PKTLINE_H
4 #include "git-compat-util.h"
5 #include "strbuf.h"
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).
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).
19 * The writing side could use stdio, but since the reading
20 * side can't, we stay with pure read/write interfaces.
22 void packet_flush(int fd);
23 void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
24 void packet_buf_flush(struct strbuf *buf);
25 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
26 int packet_flush_gently(int fd);
27 int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
28 LAST_ARG_MUST_BE_NULL
29 int packet_writel(int fd, const char *line, ...);
30 int write_packetized_from_fd(int fd_in, int fd_out);
31 int write_packetized_from_buf(const char *src_in, size_t len, int fd_out);
34 * Read a packetized line into the buffer, which must be at least size bytes
35 * long. The return value specifies the number of bytes read into the buffer.
37 * If src_buffer and *src_buffer are not NULL, it should point to a buffer
38 * containing the packet data to parse, of at least *src_len bytes. After the
39 * function returns, src_buf will be incremented and src_len decremented by the
40 * number of bytes consumed.
42 * If src_buffer (or *src_buffer) is NULL, then data is read from the
43 * descriptor "fd".
45 * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any
46 * of the following conditions:
48 * 1. Read error from descriptor.
50 * 2. Protocol error from the remote (e.g., bogus length characters).
52 * 3. Receiving a packet larger than "size" bytes.
54 * 4. Truncated output from the remote (e.g., we expected a packet but got
55 * EOF, or we got a partial packet followed by EOF).
57 * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on
58 * condition 4 (truncated input), but instead return -1. However, we will still
59 * die for the other 3 conditions.
61 * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if
62 * present) is removed from the buffer before returning.
64 #define PACKET_READ_GENTLE_ON_EOF (1u<<0)
65 #define PACKET_READ_CHOMP_NEWLINE (1u<<1)
66 int packet_read(int fd, char **src_buffer, size_t *src_len, char
67 *buffer, unsigned size, int options);
70 * Convenience wrapper for packet_read that is not gentle, and sets the
71 * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
72 * and otherwise points to a static buffer (that may be overwritten by
73 * subsequent calls). If the size parameter is not NULL, the length of the
74 * packet is written to it.
76 char *packet_read_line(int fd, int *size);
79 * Convenience wrapper for packet_read that sets the PACKET_READ_GENTLE_ON_EOF
80 * and CHOMP_NEWLINE options. The return value specifies the number of bytes
81 * read into the buffer or -1 on truncated input. If the *dst_line parameter
82 * is not NULL it will return NULL for a flush packet or when the number of
83 * bytes copied is zero and otherwise points to a static buffer (that may be
84 * overwritten by subsequent calls). If the size parameter is not NULL, the
85 * length of the packet is written to it.
87 int packet_read_line_gently(int fd, int *size, char **dst_line);
90 * Same as packet_read_line, but read from a buf rather than a descriptor;
91 * see packet_read for details on how src_* is used.
93 char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size);
96 * Reads a stream of variable sized packets until a flush packet is detected.
98 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out);
100 #define DEFAULT_PACKET_MAX 1000
101 #define LARGE_PACKET_MAX 65520
102 #define LARGE_PACKET_DATA_MAX (LARGE_PACKET_MAX - 4)
103 extern char packet_buffer[LARGE_PACKET_MAX];
105 #endif