Fix prefixing and suffixing in unbuffered fpm logging

sapi/fpm/fpm/zlog.c

@@ -323,39 +323,53 @@ static inline ssize_t zlog_stream_unbuffered_write(struct zlog_stream *stream, c
 {
 	int finished = 0;
 	const char *append;
-	size_t append_len;
+	size_t append_len = 0, available_len;
+	ssize_t written;
+
+	if (stream->len == 0) {
+		stream->len = zlog_stream_prefix_ex(stream, stream->function, stream->line);
+	}
 
 	if (stream->len + len >= zlog_limit) {
 		if (stream->wrap) {
-			if (stream->wrap_prefix != NULL) {
-				zlog_stream_direct_write_ex(
-						stream, stream->wrap_prefix, stream->wrap_prefix_len, NULL, 0);
-			}
-			len = zlog_limit - stream->len;
+			available_len = zlog_limit - stream->len;
 			if (stream->len + len == zlog_limit) {
 				append = NULL;
 				append_len = 0;
 			} else {
 				append = "\n";
 				append_len = 1;
 			}
-			if (stream->wrap_suffix) {
-				zlog_stream_direct_write(stream, buf, len);
+			if (stream->wrap_suffix && append != NULL) {
+				zlog_stream_direct_write(stream, buf, available_len);
 				zlog_stream_direct_write_ex(
 						stream, stream->wrap_suffix, stream->wrap_suffix_len, append, append_len);
 			} else {
-				zlog_stream_direct_write_ex(stream, buf, len, append, append_len);
+				zlog_stream_direct_write_ex(stream, buf, available_len, append, append_len);
 			}
+			stream->len = 0;
 			/* TODO: use loop to speed it up */
-			return len + zlog_stream_unbuffered_write(stream, buf + len, len);
+			written = zlog_stream_unbuffered_write(stream, buf + available_len, len - available_len);
+			if (written > 0) {
+				return available_len + written;
+			}
+
+			return written;
 		}
 		stream->finished = finished = 1;
 		append = (stream->len + len == zlog_limit) ? "\n" : "...\n";
 		append_len = sizeof(append) - 1;
 		len = zlog_limit - stream->len - append_len;
 	}
 
-	return zlog_stream_direct_write_ex(stream, buf, len, append, append_len);
+	written = zlog_stream_direct_write_ex(stream, buf, len, append, append_len);
+	if (written > 0) {
+		/* currently written will be always len as the write is blocking
+		 * - this should be address if we change to non-blocking write */
+		stream->len += written;
+	}
+
+	return written;
 }
 /* }}} */
 
@@ -456,14 +470,16 @@ ssize_t zlog_stream_set_wrapping_prefix(struct zlog_stream *stream, const char *
 	va_list args;
 
 	va_start(args, fmt);
-	len = vsnprintf(buf, MAX_WRAPPING_PREFIX_LENGTH, fmt, args);
+	len = vsnprintf(buf, MAX_WRAPPING_PREFIX_LENGTH - 1, fmt, args);
 	va_end(args);
 
 	stream->wrap_prefix = malloc(len);
-	if (stream->wrap_prefix != NULL) {
+	if (stream->wrap_prefix == NULL) {
 		return -1;
 	}
 	memcpy(stream->wrap_prefix, buf, len);
+	stream->wrap_prefix[len] = 0;
+	stream->wrap_prefix_len = len;
 
 	return len;
 }
@@ -603,7 +619,12 @@ zlog_bool zlog_stream_finish(struct zlog_stream *stream) /* {{{ */
 		stream->buf[stream->len++] = '\n';
 		zlog_stream_direct_write(stream, stream->buf, stream->len);
 	} else if (!stream->finished) {
-		if (stream->wrap_final_suffix != NULL) {
+		if (stream->wrap_suffix != NULL) {
+			zlog_stream_direct_write_ex(
+					stream, stream->wrap_suffix, stream->wrap_suffix_len,
+					stream->wrap_final_suffix, stream->wrap_final_suffix_len);
+			zlog_stream_direct_write(stream, "\n", 1);
+		} else if (stream->wrap_final_suffix != NULL) {
 			zlog_stream_direct_write_ex(
 					stream, stream->wrap_final_suffix, stream->wrap_final_suffix_len, "\n", 1);
 		} else {