Using the new structured printer support in sprinter.h, implement
sprinter_json_new, which returns a new JSON structured output
formatter.
The formatter prints output similar to the existing JSON, but with
differences in whitespace (mostly newlines).
---
Makefile.local | 1 +
sprinter.c | 172 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 173 insertions(+)
create mode 100644 sprinter.c
diff --git a/Makefile.local b/Makefile.local
index a890df2..8baf0c2 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -290,6 +290,7 @@ notmuch_client_srcs = \
notmuch-show.c \
notmuch-tag.c \
notmuch-time.c \
+ sprinter.c \
query-string.c \
mime-node.c \
crypto.c \
diff --git a/sprinter.c b/sprinter.c
new file mode 100644
index 0000000..649f79a
--- /dev/null
+++ b/sprinter.c
@@ -0,0 +1,172 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <talloc.h>
+#include "sprinter.h"
+
+#define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
+
+struct sprinter *
+sprinter_text = NULL;
+
+/*
+ * Every below here is the implementation of the JSON printer.
+ */
+
+struct sprinter_json
+{
+ struct sprinter vtable;
+ FILE *stream;
+ /* Top of the state stack, or NULL if the printer is not currently
+ * inside any aggregate types. */
+ struct json_state *state;
+};
+
+struct json_state
+{
+ struct json_state *parent;
+ /* True if nothing has been printed in this aggregate yet.
+ * Suppresses the comma before a value. */
+ notmuch_bool_t first;
+ /* The character that closes the current aggregate. */
+ char close;
+};
+
+/* Helper function to set up the stream to print a value. If this
+ * value follows another value, prints a comma. */
+static struct sprinter_json *
+json_begin_value(struct sprinter *sp)
+{
+ struct sprinter_json *spj = (struct sprinter_json*)sp;
+ if (spj->state) {
+ if (!spj->state->first)
+ fputs (", ", spj->stream);
+ else
+ spj->state->first = false;
+ }
+ return spj;
+}
+
+/* Helper function to begin an aggregate type. Prints the open
+ * character and pushes a new state frame. */
+static void
+json_begin_aggregate(struct sprinter *sp, char open, char close)
+{
+ struct sprinter_json *spj = json_begin_value (sp);
+ struct json_state *state = talloc (spj, struct json_state);
+
+ fputc (open, spj->stream);
+ state->parent = spj->state;
+ state->first = true;
+ state->close = close;
+ spj->state = state;
+}
+
+static void
+json_begin_map(struct sprinter *sp)
+{
+ json_begin_aggregate (sp, '{', '}');
+}
+
+static void
+json_begin_list(struct sprinter *sp)
+{
+ json_begin_aggregate (sp, '[', ']');
+}
+
+static void
+json_end(struct sprinter *sp)
+{
+ struct sprinter_json *spj = (struct sprinter_json*)sp;
+ struct json_state *state = spj->state;
+
+ fputc (spj->state->close, spj->stream);
+ spj->state = state->parent;
+ talloc_free (state);
+ if(spj->state == NULL)
+ fputc ('\n', spj->stream);
+}
+
+static void
+json_string(struct sprinter *sp, const char *val)
+{
+ static const char * const escapes[] = {
+ ['\"'] = "\\\"", ['\\'] = "\\\\", ['\b'] = "\\b",
+ ['\f'] = "\\f", ['\n'] = "\\n", ['\t'] = "\\t"
+ };
+ struct sprinter_json *spj = json_begin_value (sp);
+ fputc ('"', spj->stream);
+ for (; *val; ++val) {
+ unsigned char ch = *val;
+ if (ch < ARRAY_SIZE(escapes) && escapes[ch])
+ fputs (escapes[ch], spj->stream);
+ else if (ch >= 32)
+ fputc (ch, spj->stream);
+ else
+ fprintf (spj->stream, "\\u%04x", ch);
+ }
+ fputc ('"', spj->stream);
+}
+
+static void
+json_integer(struct sprinter *sp, int val)
+{
+ struct sprinter_json *spj = json_begin_value (sp);
+ fprintf (spj->stream, "%d", val);
+}
+
+static void
+json_boolean(struct sprinter *sp, notmuch_bool_t val)
+{
+ struct sprinter_json *spj = json_begin_value (sp);
+ fputs (val ? "true" : "false", spj->stream);
+}
+
+static void
+json_null(struct sprinter *sp)
+{
+ struct sprinter_json *spj = json_begin_value (sp);
+ fputs ("null", spj->stream);
+}
+
+static void
+json_map_key(struct sprinter *sp, const char *key)
+{
+ struct sprinter_json *spj = (struct sprinter_json*)sp;
+ json_string (sp, key);
+ fputs (": ", spj->stream);
+ spj->state->first = true;
+}
+
+static void
+json_frame(struct sprinter *sp)
+{
+ struct sprinter_json *spj = (struct sprinter_json*)sp;
+ fputc ('\n', spj->stream);
+}
+
+struct sprinter *
+sprinter_json_new(const void *ctx, FILE *stream)
+{
+ static const struct sprinter_json template = {
+ .vtable = {
+ .begin_map = json_begin_map,
+ .begin_list = json_begin_list,
+ .end = json_end,
+ .string = json_string,
+ .integer = json_integer,
+ .boolean = json_boolean,
+ .null = json_null,
+ .map_key = json_map_key,
+ .frame = json_frame,
+ }
+ };
+ struct sprinter_json *res;
+
+ res = talloc (ctx, struct sprinter_json);
+ if (!res)
+ return NULL;
+
+ *res = template;
+ res->stream = stream;
+ return &res->vtable;
+}
--
1.7.11.1
