1 files changed, 373 insertions, 0 deletions
diff --git a/pkt-line.c b/pkt-line.c
new file mode 100644
index 0000000000..93ea311443
--- /dev/null
+++ b/pkt-line.c
@@ -0,0 +1,373 @@
+#include "cache.h"
+#include "pkt-line.h"
+#include "run-command.h"
+
+char packet_buffer[LARGE_PACKET_MAX];
+static const char *packet_trace_prefix = "git";
+static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
+static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
+
+void packet_trace_identity(const char *prog)
+{
+	packet_trace_prefix = xstrdup(prog);
+}
+
+static const char *get_trace_prefix(void)
+{
+	return in_async() ? "sideband" : packet_trace_prefix;
+}
+
+static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
+{
+	if (!sideband) {
+		trace_verbatim(&trace_pack, buf, len);
+		return 1;
+	} else if (len && *buf == '\1') {
+		trace_verbatim(&trace_pack, buf + 1, len - 1);
+		return 1;
+	} else {
+		/* it's another non-pack sideband */
+		return 0;
+	}
+}
+
+static void packet_trace(const char *buf, unsigned int len, int write)
+{
+	int i;
+	struct strbuf out;
+	static int in_pack, sideband;
+
+	if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
+		return;
+
+	if (in_pack) {
+		if (packet_trace_pack(buf, len, sideband))
+			return;
+	} else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
+		in_pack = 1;
+		sideband = *buf == '\1';
+		packet_trace_pack(buf, len, sideband);
+
+		/*
+		 * Make a note in the human-readable trace that the pack data
+		 * started.
+		 */
+		buf = "PACK ...";
+		len = strlen(buf);
+	}
+
+	if (!trace_want(&trace_packet))
+		return;
+
+	/* +32 is just a guess for header + quoting */
+	strbuf_init(&out, len+32);
+
+	strbuf_addf(&out, "packet: %12s%c ",
+		    get_trace_prefix(), write ? '>' : '<');
+
+	/* 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]);
+	}
+
+	strbuf_addch(&out, '\n');
+	trace_strbuf(&trace_packet, &out);
+	strbuf_release(&out);
+}
+
+/*
+ * If we buffered things up above (we don't, but we should),
+ * we'd flush it here
+ */
+void packet_flush(int fd)
+{
+	packet_trace("0000", 4, 1);
+	write_or_die(fd, "0000", 4);
+}
+
+int packet_flush_gently(int fd)
+{
+	packet_trace("0000", 4, 1);
+	if (write_in_full(fd, "0000", 4) < 0)
+		return error("flush packet write failed");
+	return 0;
+}
+
+void packet_buf_flush(struct strbuf *buf)
+{
+	packet_trace("0000", 4, 1);
+	strbuf_add(buf, "0000", 4);
+}
+
+static void set_packet_header(char *buf, const int size)
+{
+	static char hexchar[] = "0123456789abcdef";
+
+	#define hex(a) (hexchar[(a) & 15])
+	buf[0] = hex(size >> 12);
+	buf[1] = hex(size >> 8);
+	buf[2] = hex(size >> 4);
+	buf[3] = hex(size);
+	#undef hex
+}
+
+static void format_packet(struct strbuf *out, const char *fmt, va_list args)
+{
+	size_t orig_len, n;
+
+	orig_len = out->len;
+	strbuf_addstr(out, "0000");
+	strbuf_vaddf(out, fmt, args);
+	n = out->len - orig_len;
+
+	if (n > LARGE_PACKET_MAX)
+		die("protocol error: impossibly long line");
+
+	set_packet_header(&out->buf[orig_len], n);
+	packet_trace(out->buf + orig_len + 4, n - 4, 1);
+}
+
+static int packet_write_fmt_1(int fd, int gently,
+			      const char *fmt, va_list args)
+{
+	static struct strbuf buf = STRBUF_INIT;
+
+	strbuf_reset(&buf);
+	format_packet(&buf, fmt, args);
+	if (write_in_full(fd, buf.buf, buf.len) < 0) {
+		if (!gently) {
+			check_pipe(errno);
+			die_errno("packet write with format failed");
+		}
+		return error("packet write with format failed");
+	}
+
+	return 0;
+}
+
+void packet_write_fmt(int fd, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	packet_write_fmt_1(fd, 0, fmt, args);
+	va_end(args);
+}
+
+int packet_write_fmt_gently(int fd, const char *fmt, ...)
+{
+	int status;
+	va_list args;
+
+	va_start(args, fmt);
+	status = packet_write_fmt_1(fd, 1, fmt, args);
+	va_end(args);
+	return status;
+}
+
+static int packet_write_gently(const int fd_out, const char *buf, size_t size)
+{
+	static char packet_write_buffer[LARGE_PACKET_MAX];
+	size_t packet_size;
+
+	if (size > sizeof(packet_write_buffer) - 4)
+		return error("packet write failed - data exceeds max packet size");
+
+	packet_trace(buf, size, 1);
+	packet_size = size + 4;
+	set_packet_header(packet_write_buffer, packet_size);
+	memcpy(packet_write_buffer + 4, buf, size);
+	if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
+		return error("packet write failed");
+	return 0;
+}
+
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	format_packet(buf, fmt, args);
+	va_end(args);
+}
+
+int write_packetized_from_fd(int fd_in, int fd_out)
+{
+	static char buf[LARGE_PACKET_DATA_MAX];
+	int err = 0;
+	ssize_t bytes_to_write;
+
+	while (!err) {
+		bytes_to_write = xread(fd_in, buf, sizeof(buf));
+		if (bytes_to_write < 0)
+			return COPY_READ_ERROR;
+		if (bytes_to_write == 0)
+			break;
+		err = packet_write_gently(fd_out, buf, bytes_to_write);
+	}
+	if (!err)
+		err = packet_flush_gently(fd_out);
+	return err;
+}
+
+int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
+{
+	int err = 0;
+	size_t bytes_written = 0;
+	size_t bytes_to_write;
+
+	while (!err) {
+		if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
+			bytes_to_write = LARGE_PACKET_DATA_MAX;
+		else
+			bytes_to_write = len - bytes_written;
+		if (bytes_to_write == 0)
+			break;
+		err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
+		bytes_written += bytes_to_write;
+	}
+	if (!err)
+		err = packet_flush_gently(fd_out);
+	return err;
+}
+
+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;
+}
+
+static int packet_length(const char *linelen)
+{
+	int val = hex2chr(linelen);
+	return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
+}
+
+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);
+	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 > 0) ? packet_buffer : NULL;
+}
+
+char *packet_read_line(int fd, int *len_p)
+{
+	return packet_read_line_generic(fd, NULL, NULL, len_p);
+}
+
+int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
+{
+	int len = packet_read(fd, NULL, NULL,
+			      packet_buffer, sizeof(packet_buffer),
+			      PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
+	if (dst_len)
+		*dst_len = len;
+	if (dst_line)
+		*dst_line = (len > 0) ? packet_buffer : NULL;
+	return len;
+}
+
+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);
+}
+
+ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
+{
+	int packet_len;
+
+	size_t orig_len = sb_out->len;
+	size_t orig_alloc = sb_out->alloc;
+
+	for (;;) {
+		strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
+		packet_len = packet_read(fd_in, NULL, NULL,
+			/* strbuf_grow() above always allocates one extra byte to
+			 * store a '\0' at the end of the string. packet_read()
+			 * writes a '\0' extra byte at the end, too. Let it know
+			 * that there is already room for the extra byte.
+			 */
+			sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
+			PACKET_READ_GENTLE_ON_EOF);
+		if (packet_len <= 0)
+			break;
+		sb_out->len += packet_len;
+	}
+
+	if (packet_len < 0) {
+		if (orig_alloc == 0)
+			strbuf_release(sb_out);
+		else
+			strbuf_setlen(sb_out, orig_len);
+		return packet_len;
+	}
+	return sb_out->len - orig_len;
+}