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_fmt(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 into the buffer, which must be at least size bytes 29 * long. The return value specifies the number of bytes read into the buffer. 30 * 31 * If src_buffer and *src_buffer are not NULL, it should point to a buffer 32 * containing the packet data to parse, of at least *src_len bytes. After the 33 * function returns, src_buf will be incremented and src_len decremented by the 34 * number of bytes consumed. 35 * 36 * If src_buffer (or *src_buffer) is NULL, then data is read from the 37 * descriptor "fd". 38 * 39 * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any 40 * of the following conditions: 41 * 42 * 1. Read error from descriptor. 43 * 44 * 2. Protocol error from the remote (e.g., bogus length characters). 45 * 46 * 3. Receiving a packet larger than "size" bytes. 47 * 48 * 4. Truncated output from the remote (e.g., we expected a packet but got 49 * EOF, or we got a partial packet followed by EOF). 50 * 51 * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on 52 * condition 4 (truncated input), but instead return -1. However, we will still 53 * die for the other 3 conditions. 54 * 55 * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if 56 * present) is removed from the buffer before returning. 57 */ 58#define PACKET_READ_GENTLE_ON_EOF (1u<<0) 59#define PACKET_READ_CHOMP_NEWLINE (1u<<1) 60int packet_read(int fd, char **src_buffer, size_t *src_len, char 61 *buffer, unsigned size, int options); 62 63/* 64 * Convenience wrapper for packet_read that is not gentle, and sets the 65 * CHOMP_NEWLINE option. The return value is NULL for a flush packet, 66 * and otherwise points to a static buffer (that may be overwritten by 67 * subsequent calls). If the size parameter is not NULL, the length of the 68 * packet is written to it. 69 */ 70char *packet_read_line(int fd, int *size); 71 72/* 73 * Same as packet_read_line, but read from a buf rather than a descriptor; 74 * see packet_read for details on how src_* is used. 75 */ 76char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size); 77 78#define DEFAULT_PACKET_MAX 1000 79#define LARGE_PACKET_MAX 65520 80extern char packet_buffer[LARGE_PACKET_MAX]; 81 82#endif