decode: concentrate JSON formatting in a single location

[sigrok-cli.git] / decode.c

diff --git a/decode.c b/decode.c
index 06400f36e87516caa56a97d2cd14e5e9bf88d9fb..e0b27fd2938636350a4ab9b70e8b709f6ab3a8e8 100644 (file)
--- a/decode.c
+++ b/decode.c
@@ -487,27 +487,56 @@ int setup_pd_binary(char *opt_pd_binary)
  * the output and late flush (and to keep the state strictly local to the
  * routine). Some additional complexity due to JSON's inability to handle
  * a trailing comma at the last item. Code phrased such that text literals
- * are kept in their order of appearance in the output text.
+ * are kept in their order of appearance in the output (where possible).
  */
-static void jsontrace_open_close(gboolean is_close_req)
+static void jsontrace_open_close(gboolean is_close_req,
+       gboolean open_item, gboolean close_item)
 {
-       static gboolean is_opened;
+       static gboolean is_file_open;
+       static gboolean is_item_open;
 
-       if (!is_close_req) {
-               if (!is_opened) {
+       if (is_close_req && is_item_open)
+               close_item = TRUE;
+
+       /* Automatic file header, and array item separation. */
+       if (open_item) {
+               if (!is_file_open)
                        printf("{\"traceEvents\": [\n");
-                       is_opened = TRUE;
-               } else {
-                       printf(",\n");
+               if (is_item_open) {
+                       printf("}");
+                       is_item_open = FALSE;
                }
-       } else {
-               if (is_opened) {
-                       printf("\n");
-                       printf("]}\n");
-                       fflush(stdout);
+               if (is_file_open) {
+                       printf(",\n");
                }
-               is_opened = FALSE;
+               is_file_open = TRUE;
+       }
+
+       /* Array item open/append/close. */
+       if (open_item) {
+               printf("{");
+               is_item_open = TRUE;
        }
+       if (!open_item && !close_item && !is_close_req) {
+               printf(", ");
+               is_item_open = TRUE;
+       }
+       if (close_item) {
+               printf("}");
+               is_item_open = FALSE;
+       }
+
+       /* Automatic file footer on shutdown. */
+       if (is_close_req && is_file_open) {
+               printf("\n");
+               printf("]}\n");
+       }
+       if (is_close_req)
+               is_file_open = FALSE;
+
+       /* Flush at end of lines, or end of file. */
+       if (close_item || is_close_req)
+               fflush(stdout);
 }
 
 /* Convert uint64 sample number to double timestamp in microseconds. */
@@ -565,29 +594,37 @@ static void jsontrace_annotation(struct srd_decoder *dec,
         * BEWARE of the unfortunate JSON format comma limitation. And
         * some of the output formatting is motivated by the desire to
         * further reduce text size, by eliminating some of the spaces.
+        * TODO Want to introduce a cJSON dependency to delegate the
+        * construction of output text?
         *
         * This implementation is strictly compatible to the initial
         * implementation. Which might change in the future to increase
         * readability of the output to humans, by generating a layout
         * which is closer to other output modes.
         */
-       jsontrace_open_close(FALSE);
-       printf("{");
+       jsontrace_open_close(FALSE, TRUE, FALSE);
        printf("\"%s\": \"%s\"", "name", pda->ann_text[0]);
-       printf(", \"%s\": \"%s\"", "ph", "B");
-       printf(", \"%s\": \"%s\"", "pid", pdata->pdo->proto_id);
-       printf(", \"%s\": \"%s\"", "tid", row_text);
-       printf(", \"%s\": %lf", "ts", jsontrace_ts_usec(pdata->start_sample));
-       printf("}");
-
-       jsontrace_open_close(FALSE);
-       printf("{");
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": \"%s\"", "ph", "B");
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": \"%s\"", "pid", pdata->pdo->proto_id);
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": \"%s\"", "tid", row_text);
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": %lf", "ts", jsontrace_ts_usec(pdata->start_sample));
+
+       jsontrace_open_close(FALSE, TRUE, FALSE);
        printf("\"%s\": \"%s\"", "name", pda->ann_text[0]);
-       printf(", \"%s\": \"%s\"", "ph", "E");
-       printf(", \"%s\": \"%s\"", "pid", pdata->pdo->proto_id);
-       printf(", \"%s\": \"%s\"", "tid", row_text);
-       printf(", \"%s\": %lf", "ts", jsontrace_ts_usec(pdata->end_sample));
-       printf("}");
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": \"%s\"", "ph", "E");
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": \"%s\"", "pid", pdata->pdo->proto_id);
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": \"%s\"", "tid", row_text);
+       jsontrace_open_close(FALSE, FALSE, FALSE);
+       printf("\"%s\": %lf", "ts", jsontrace_ts_usec(pdata->end_sample));
+
+       jsontrace_open_close(FALSE, FALSE, TRUE);
 }
 
 void show_pd_annotations(struct srd_proto_data *pdata, void *cb_data)
@@ -721,12 +758,12 @@ void show_pd_binary(struct srd_proto_data *pdata, void *cb_data)
 void show_pd_prepare(void)
 {
        if (opt_pd_jsontrace)
-               jsontrace_open_close(TRUE);
+               jsontrace_open_close(TRUE, FALSE, FALSE);
 }
 
 void show_pd_close(void)
 {
        if (opt_pd_jsontrace)
-               jsontrace_open_close(TRUE);
+               jsontrace_open_close(TRUE, FALSE, FALSE);
 }
 #endif