read-cache: fix index corruption with index v4
[gitweb.git] / pkt-line.c
index 30489c60b1d3f8acc002fad31aa68b528757c8da..7db9119573abe2c8308bd37c670c027c07b425c8 100644 (file)
@@ -91,16 +91,34 @@ void packet_flush(int fd)
        write_or_die(fd, "0000", 4);
 }
 
+int packet_flush_gently(int fd)
+{
+       packet_trace("0000", 4, 1);
+       if (write_in_full(fd, "0000", 4) == 4)
+               return 0;
+       return error("flush packet write failed");
+}
+
 void packet_buf_flush(struct strbuf *buf)
 {
        packet_trace("0000", 4, 1);
        strbuf_add(buf, "0000", 4);
 }
 
-#define hex(a) (hexchar[(a) & 15])
-static void format_packet(struct strbuf *out, const char *fmt, va_list args)
+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;
@@ -111,23 +129,63 @@ static void format_packet(struct strbuf *out, const char *fmt, va_list args)
        if (n > LARGE_PACKET_MAX)
                die("protocol error: impossibly long line");
 
-       out->buf[orig_len + 0] = hex(n >> 12);
-       out->buf[orig_len + 1] = hex(n >> 8);
-       out->buf[orig_len + 2] = hex(n >> 4);
-       out->buf[orig_len + 3] = hex(n);
+       set_packet_header(&out->buf[orig_len], n);
        packet_trace(out->buf + orig_len + 4, n - 4, 1);
 }
 
-void packet_write(int fd, const char *fmt, ...)
+static int packet_write_fmt_1(int fd, int gently,
+                             const char *fmt, va_list args)
+{
+       struct strbuf buf = STRBUF_INIT;
+       ssize_t count;
+
+       format_packet(&buf, fmt, args);
+       count = write_in_full(fd, buf.buf, buf.len);
+       if (count == buf.len)
+               return 0;
+
+       if (!gently) {
+               check_pipe(errno);
+               die_errno("packet write with format failed");
+       }
+       return error("packet write with format failed");
+}
+
+void packet_write_fmt(int fd, const char *fmt, ...)
 {
-       static struct strbuf buf = STRBUF_INIT;
        va_list args;
 
-       strbuf_reset(&buf);
        va_start(args, fmt);
-       format_packet(&buf, fmt, args);
+       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);
-       write_or_die(fd, buf.buf, buf.len);
+       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) == packet_size)
+               return 0;
+       return error("packet write failed");
 }
 
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
@@ -139,6 +197,46 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
        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)
 {
@@ -217,7 +315,7 @@ static char *packet_read_line_generic(int fd,
                              PACKET_READ_CHOMP_NEWLINE);
        if (dst_len)
                *dst_len = len;
-       return len ? packet_buffer : NULL;
+       return (len > 0) ? packet_buffer : NULL;
 }
 
 char *packet_read_line(int fd, int *len_p)
@@ -225,7 +323,51 @@ 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;
+}