Make the MSVC projects use PDB/IDB files named after the project
[git/dscho.git] / pkt-line.c
blobb691abebd79b40f096b28b5dbcb433f01bc0e949
1 #include "cache.h"
2 #include "pkt-line.h"
4 /*
5 * Write a packetized stream, where each line is preceded by
6 * its length (including the header) as a 4-byte hex number.
7 * A length of 'zero' means end of stream (and a length of 1-3
8 * would be an error).
10 * This is all pretty stupid, but we use this packetized line
11 * format to make a streaming format possible without ever
12 * over-running the read buffers. That way we'll never read
13 * into what might be the pack data (which should go to another
14 * process entirely).
16 * The writing side could use stdio, but since the reading
17 * side can't, we stay with pure read/write interfaces.
19 ssize_t safe_write(int fd, const void *buf, ssize_t n)
21 ssize_t nn = n;
22 while (n) {
23 int ret = xwrite(fd, buf, n);
24 if (ret > 0) {
25 buf = (char *) buf + ret;
26 n -= ret;
27 continue;
29 if (!ret)
30 die("write error (disk full?)");
31 die_errno("write error");
33 return nn;
37 * If we buffered things up above (we don't, but we should),
38 * we'd flush it here
40 void packet_flush(int fd)
42 safe_write(fd, "0000", 4);
45 #define hex(a) (hexchar[(a) & 15])
46 void packet_write(int fd, const char *fmt, ...)
48 static char buffer[1000];
49 static char hexchar[] = "0123456789abcdef";
50 va_list args;
51 unsigned n;
53 va_start(args, fmt);
54 n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
55 va_end(args);
56 if (n >= sizeof(buffer)-4)
57 die("protocol error: impossibly long line");
58 n += 4;
59 buffer[0] = hex(n >> 12);
60 buffer[1] = hex(n >> 8);
61 buffer[2] = hex(n >> 4);
62 buffer[3] = hex(n);
63 safe_write(fd, buffer, n);
66 static void safe_read(int fd, void *buffer, unsigned size)
68 ssize_t ret = read_in_full(fd, buffer, size);
69 if (ret < 0)
70 die_errno("read error");
71 else if (ret < size)
72 die("The remote end hung up unexpectedly");
75 int packet_read_line(int fd, char *buffer, unsigned size)
77 int n;
78 unsigned len;
79 char linelen[4];
81 safe_read(fd, linelen, 4);
83 len = 0;
84 for (n = 0; n < 4; n++) {
85 unsigned char c = linelen[n];
86 len <<= 4;
87 if (c >= '0' && c <= '9') {
88 len += c - '0';
89 continue;
91 if (c >= 'a' && c <= 'f') {
92 len += c - 'a' + 10;
93 continue;
95 if (c >= 'A' && c <= 'F') {
96 len += c - 'A' + 10;
97 continue;
99 die("protocol error: bad line length character");
101 if (!len)
102 return 0;
103 len -= 4;
104 if (len >= size)
105 die("protocol error: bad line length %d", len);
106 safe_read(fd, buffer, len);
107 buffer[len] = 0;
108 return len;