From: Peter Feigl <craven@gmx.net>
To: notmuch@notmuchmail.org
Subject: [PATCH v5 2/3] Add structured output formatter for JSON and text.
Date: Fri, 13 Jul 2012 10:11:36 +0200
Message-Id: <1342167097-25012-3-git-send-email-craven@gmx.net>
In-Reply-To: <1342167097-25012-1-git-send-email-craven@gmx.net>
References: <20120710191331.GE7332@mit.edu>
	<1342167097-25012-1-git-send-email-craven@gmx.net>
Precedence: list

From: <craven@gmx.net>

Using the new structured printer support in sprinter.h, implement
sprinter_json_create, which returns a new JSON structured output
formatter. The formatter prints output similar to the existing JSON, but
with differences in whitespace (mostly newlines, --output=summary prints
the entire message summary on one line, not split across multiple lines).

Also implement a "structured" formatter that prints the current plain
text format. This passes all tests, but the exact formatting is probably
specific to notmuch-search and cannot easily (if at all) be adapted to
be used across all of notmuch-{search,reply,show,...}.
---
 Makefile.local         |   2 +
 sprinter-json.c        | 184 +++++++++++++++++++++++++++++++++++++++++++++++
 sprinter-text-search.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++++
 sprinter.h             |   8 +++
 4 files changed, 384 insertions(+)
 create mode 100644 sprinter-json.c
 create mode 100644 sprinter-text-search.c

diff --git a/Makefile.local b/Makefile.local
index a890df2..b6c7e0c 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -290,6 +290,8 @@ notmuch_client_srcs =		\
 	notmuch-show.c		\
 	notmuch-tag.c		\
 	notmuch-time.c		\
+	sprinter-json.c		\
+	sprinter-text-search.c	\
 	query-string.c		\
 	mime-node.c		\
 	crypto.c		\
diff --git a/sprinter-json.c b/sprinter-json.c
new file mode 100644
index 0000000..215151d
--- /dev/null
+++ b/sprinter-json.c
@@ -0,0 +1,184 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <talloc.h>
+#include "sprinter.h"
+
+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;
+
+    /* A flag to signify that a separator should be inserted in the
+     * output as soon as possible.
+     */
+    notmuch_bool_t insert_separator;
+};
+
+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) {
+	    fputc (',', spj->stream);
+	    if (spj->insert_separator) {
+		fputc ('\n', spj->stream);
+		spj->insert_separator = FALSE;
+	    } else
+		fputc (' ', 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_set_prefix (unused (struct sprinter *sp), unused (const char *name))
+{
+}
+
+static void
+json_separator (struct sprinter *sp)
+{
+    struct sprinter_json *spj = (struct sprinter_json *) sp;
+
+    spj->insert_separator = TRUE;
+}
+
+struct sprinter *
+sprinter_json_create (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,
+	    .separator = json_separator,
+	    .set_prefix = json_set_prefix,
+	}
+    };
+    struct sprinter_json *res;
+
+    res = talloc (ctx, struct sprinter_json);
+    if (! res)
+	return NULL;
+
+    *res = template;
+    res->stream = stream;
+    return &res->vtable;
+}
diff --git a/sprinter-text-search.c b/sprinter-text-search.c
new file mode 100644
index 0000000..95ed9cb
--- /dev/null
+++ b/sprinter-text-search.c
@@ -0,0 +1,190 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <talloc.h>
+#include "sprinter.h"
+
+/* "Structured printer" interface for unstructured text printing.
+ * This is at best a misuse of the interface, but it simplifies the code
+ * in notmuch-search.c considerably.
+ */
+
+struct sprinter_text_search {
+    struct sprinter vtable;
+    FILE *stream;
+
+    /* The current name or prefix to be printed with string/integer/boolean
+     * data.
+     */
+    const char *current_name;
+
+    /* A flag to indicate if this is the first tag. Used in list of tags
+     * for summary.
+     */
+    notmuch_bool_t first_tag;
+};
+
+/* struct text_search_state { */
+/*     struct text_search_state *parent; */
+/* }; */
+
+static notmuch_bool_t
+current_context (struct sprinter_text_search *sptxt, const char *marker)
+{
+    return (sptxt->current_name != NULL
+	    && ! strncmp (marker, sptxt->current_name, strlen (marker)));
+}
+
+static void
+print_sanitized_string (FILE *stream, const char *str)
+{
+    if (NULL == str)
+	return;
+
+    for (; *str; str++) {
+	if ((unsigned char) (*str) < 32)
+	    fputc ('?', stream);
+	else
+	    fputc (*str, stream);
+    }
+}
+
+static void
+text_search_begin_map (unused (struct sprinter *sp))
+{
+}
+
+static void
+text_search_begin_list (struct sprinter *sp)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    if (current_context (sptxt, "tags")) {
+	fputs (" (", sptxt->stream);
+	sptxt->first_tag = TRUE;
+    }
+}
+
+static void
+text_search_end (struct sprinter *sp)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    if (current_context (sptxt, "tags")) {
+	fputc (')', sptxt->stream);
+	sptxt->current_name = NULL;
+    }
+}
+
+static void
+text_search_string (struct sprinter *sp, const char *val)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    if (sptxt->current_name != NULL) {
+	if (current_context (sptxt, "thread"))
+	    fprintf ( sptxt->stream, "thread:%s ", val);
+	else if (current_context (sptxt, "date_relative"))
+	    fprintf ( sptxt->stream, "%12s ", val);
+	else if (current_context (sptxt, "authors")) {
+	    print_sanitized_string (sptxt->stream, val);
+	    fputs ("; ", sptxt->stream);
+	} else if (current_context (sptxt, "subject"))
+	    print_sanitized_string (sptxt->stream, val);
+	else if (current_context (sptxt, "tags")) {
+	    if (! sptxt->first_tag)
+		fputc (' ', sptxt->stream);
+	    else
+		sptxt->first_tag = FALSE;
+
+	    fputs (val, sptxt->stream);
+	} else {
+	    fputs (sptxt->current_name, sptxt->stream);
+	    fputc (':', sptxt->stream);
+	    fputs (val, sptxt->stream);
+	}
+    } else {
+	fputs (val, sptxt->stream);
+    }
+}
+
+static void
+text_search_integer (struct sprinter *sp, int val)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    if (sptxt->current_name != NULL) {
+	if (current_context (sptxt, "matched"))
+	    fprintf ( sptxt->stream, "[%d/", val);
+	else if (current_context (sptxt, "total"))
+	    fprintf ( sptxt->stream, "%d] ", val);
+    } else
+	fprintf (sptxt->stream, "%d", val);
+}
+
+static void
+text_search_boolean (struct sprinter *sp, notmuch_bool_t val)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    fputs (val ? "true" : "false", sptxt->stream);
+}
+
+static void
+text_search_null (struct sprinter *sp)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    fputs ("null", sptxt->stream);
+}
+
+static void
+text_search_map_key (struct sprinter *sp, const char *key)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    sptxt->current_name = key;
+}
+
+static void
+text_search_separator (struct sprinter *sp)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    fputc ('\n', sptxt->stream);
+}
+
+static void
+text_search_set_prefix (struct sprinter *sp, const char *name)
+{
+    struct sprinter_text_search *sptxt = (struct sprinter_text_search *) sp;
+
+    sptxt->current_name = name;
+}
+
+struct sprinter *
+sprinter_text_search_create (const void *ctx, FILE *stream)
+{
+    static const struct sprinter_text_search template = {
+	.vtable = {
+	    .begin_map = text_search_begin_map,
+	    .begin_list = text_search_begin_list,
+	    .end = text_search_end,
+	    .string = text_search_string,
+	    .integer = text_search_integer,
+	    .boolean = text_search_boolean,
+	    .null = text_search_null,
+	    .map_key = text_search_map_key,
+	    .separator = text_search_separator,
+	    .set_prefix = text_search_set_prefix,
+	}
+    };
+    struct sprinter_text_search *res;
+
+    res = talloc (ctx, struct sprinter_text_search);
+    if (! res)
+	return NULL;
+
+    *res = template;
+    res->stream = stream;
+    return &res->vtable;
+}
diff --git a/sprinter.h b/sprinter.h
index c9cd6a6..4241d65 100644
--- a/sprinter.h
+++ b/sprinter.h
@@ -47,4 +47,12 @@ typedef struct sprinter {
     void (*separator)(struct sprinter *);
 } sprinter_t;
 
+/* Create a new unstructured printer that emits the default Text format for search. */
+struct sprinter *
+sprinter_text_search_create (const void *ctx, FILE *stream);
+
+/* Create a new structure printer that emits JSON. */
+struct sprinter *
+sprinter_json_create (const void *ctx, FILE *stream);
+
 #endif // NOTMUCH_SPRINTER_H
-- 
1.7.11.1