#include "cache.h"
#include "pkt-line.h"
-/*
- * Write a packetized stream, where each line is preceded by
- * its length (including the header) as a 4-byte hex number.
- * A length of 'zero' means end of stream (and a length of 1-3
- * would be an error).
- *
- * This is all pretty stupid, but we use this packetized line
- * format to make a streaming format possible without ever
- * over-running the read buffers. That way we'll never read
- * into what might be the pack data (which should go to another
- * process entirely).
- *
- * The writing side could use stdio, but since the reading
- * side can't, we stay with pure read/write interfaces.
- */
-ssize_t safe_write(int fd, const void *buf, ssize_t n)
+char packet_buffer[LARGE_PACKET_MAX];
+static const char *packet_trace_prefix = "git";
+static const char trace_key[] = "GIT_TRACE_PACKET";
+
+void packet_trace_identity(const char *prog)
{
- ssize_t nn = n;
- while (n) {
- int ret = xwrite(fd, buf, n);
- if (ret > 0) {
- buf = (char *) buf + ret;
- n -= ret;
- continue;
+ packet_trace_prefix = xstrdup(prog);
+}
+
+static void packet_trace(const char *buf, unsigned int len, int write)
+{
+ int i;
+ struct strbuf out;
+
+ if (!trace_want(trace_key))
+ return;
+
+ /* +32 is just a guess for header + quoting */
+ strbuf_init(&out, len+32);
+
+ strbuf_addf(&out, "packet: %12s%c ",
+ packet_trace_prefix, write ? '>' : '<');
+
+ if ((len >= 4 && !prefixcmp(buf, "PACK")) ||
+ (len >= 5 && !prefixcmp(buf+1, "PACK"))) {
+ strbuf_addstr(&out, "PACK ...");
+ unsetenv(trace_key);
+ }
+ else {
+ /* XXX we should really handle printable utf8 */
+ for (i = 0; i < len; i++) {
+ /* suppress newlines */
+ if (buf[i] == '\n')
+ continue;
+ if (buf[i] >= 0x20 && buf[i] <= 0x7e)
+ strbuf_addch(&out, buf[i]);
+ else
+ strbuf_addf(&out, "\\%o", buf[i]);
}
- if (!ret)
- die("write error (disk full?)");
- die("write error (%s)", strerror(errno));
}
- return nn;
+
+ strbuf_addch(&out, '\n');
+ trace_strbuf(trace_key, &out);
+ strbuf_release(&out);
}
/*
*/
void packet_flush(int fd)
{
- safe_write(fd, "0000", 4);
+ packet_trace("0000", 4, 1);
+ write_or_die(fd, "0000", 4);
+}
+
+void packet_buf_flush(struct strbuf *buf)
+{
+ packet_trace("0000", 4, 1);
+ strbuf_add(buf, "0000", 4);
}
#define hex(a) (hexchar[(a) & 15])
-void packet_write(int fd, const char *fmt, ...)
+static char buffer[1000];
+static unsigned format_packet(const char *fmt, va_list args)
{
- static char buffer[1000];
static char hexchar[] = "0123456789abcdef";
- va_list args;
unsigned n;
- va_start(args, fmt);
n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
- va_end(args);
if (n >= sizeof(buffer)-4)
die("protocol error: impossibly long line");
n += 4;
buffer[1] = hex(n >> 8);
buffer[2] = hex(n >> 4);
buffer[3] = hex(n);
- safe_write(fd, buffer, n);
+ packet_trace(buffer+4, n-4, 1);
+ return n;
}
-static void safe_read(int fd, void *buffer, unsigned size)
+void packet_write(int fd, const char *fmt, ...)
{
- ssize_t ret = read_in_full(fd, buffer, size);
- if (ret < 0)
- die("read error (%s)", strerror(errno));
- else if (ret < size)
+ va_list args;
+ unsigned n;
+
+ va_start(args, fmt);
+ n = format_packet(fmt, args);
+ va_end(args);
+ write_or_die(fd, buffer, n);
+}
+
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
+{
+ va_list args;
+ unsigned n;
+
+ va_start(args, fmt);
+ n = format_packet(fmt, args);
+ va_end(args);
+ strbuf_add(buf, buffer, n);
+}
+
+static int get_packet_data(int fd, char **src_buf, size_t *src_size,
+ void *dst, unsigned size, int options)
+{
+ ssize_t ret;
+
+ if (fd >= 0 && src_buf && *src_buf)
+ die("BUG: multiple sources given to packet_read");
+
+ /* Read up to "size" bytes from our source, whatever it is. */
+ if (src_buf && *src_buf) {
+ ret = size < *src_size ? size : *src_size;
+ memcpy(dst, *src_buf, ret);
+ *src_buf += ret;
+ *src_size -= ret;
+ } else {
+ ret = read_in_full(fd, dst, size);
+ if (ret < 0)
+ die_errno("read error");
+ }
+
+ /* And complain if we didn't get enough bytes to satisfy the read. */
+ if (ret < size) {
+ if (options & PACKET_READ_GENTLE_ON_EOF)
+ return -1;
+
die("The remote end hung up unexpectedly");
+ }
+
+ return ret;
}
-int packet_read_line(int fd, char *buffer, unsigned size)
+static int packet_length(const char *linelen)
{
int n;
- unsigned len;
- char linelen[4];
-
- safe_read(fd, linelen, 4);
+ int len = 0;
- len = 0;
for (n = 0; n < 4; n++) {
unsigned char c = linelen[n];
len <<= 4;
len += c - 'A' + 10;
continue;
}
- die("protocol error: bad line length character");
+ return -1;
}
- if (!len)
+ return len;
+}
+
+int packet_read(int fd, char **src_buf, size_t *src_len,
+ char *buffer, unsigned size, int options)
+{
+ int len, ret;
+ char linelen[4];
+
+ ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
+ if (ret < 0)
+ return ret;
+ len = packet_length(linelen);
+ if (len < 0)
+ die("protocol error: bad line length character: %.4s", linelen);
+ if (!len) {
+ packet_trace("0000", 4, 0);
return 0;
+ }
len -= 4;
if (len >= size)
die("protocol error: bad line length %d", len);
- safe_read(fd, buffer, len);
+ ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
+ if (ret < 0)
+ return ret;
+
+ if ((options & PACKET_READ_CHOMP_NEWLINE) &&
+ len && buffer[len-1] == '\n')
+ len--;
+
buffer[len] = 0;
+ packet_trace(buffer, len, 0);
return len;
}
+
+static char *packet_read_line_generic(int fd,
+ char **src, size_t *src_len,
+ int *dst_len)
+{
+ int len = packet_read(fd, src, src_len,
+ packet_buffer, sizeof(packet_buffer),
+ PACKET_READ_CHOMP_NEWLINE);
+ if (dst_len)
+ *dst_len = len;
+ return len ? packet_buffer : NULL;
+}
+
+char *packet_read_line(int fd, int *len_p)
+{
+ return packet_read_line_generic(fd, NULL, NULL, len_p);
+}
+
+char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
+{
+ return packet_read_line_generic(-1, src, src_len, dst_len);
+}