Add structured output formatter for JSON and plain text (but don't use them yet).

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 for plain text that prints
prefixed strings, to be used with notmuch-search.c plain text output.
This commit is contained in:
craven@gmx.net 2012-07-23 12:39:45 +02:00 committed by David Bremner
parent 41becc0c9d
commit 36522fca1c
4 changed files with 325 additions and 0 deletions

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@ -290,6 +290,8 @@ notmuch_client_srcs = \
notmuch-show.c \
notmuch-tag.c \
notmuch-time.c \
sprinter-json.c \
sprinter-text.c \
query-string.c \
mime-node.c \
crypto.c \

187
sprinter-json.c Normal file
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@ -0,0 +1,187 @@
#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,
.is_text_printer = FALSE,
}
};
struct sprinter_json *res;
res = talloc (ctx, struct sprinter_json);
if (! res)
return NULL;
*res = template;
res->stream = stream;
return &res->vtable;
}

126
sprinter-text.c Normal file
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@ -0,0 +1,126 @@
#include <stdbool.h>
#include <stdio.h>
#include <talloc.h>
#include "sprinter.h"
/* "Structured printer" interface for unstructured text printing.
* Note that --output=summary is dispatched and formatted in
* notmuch-search.c, the code in this file is only used for all other
* output types.
*/
struct sprinter_text {
struct sprinter vtable;
FILE *stream;
/* The current prefix to be printed with string/integer/boolean
* data.
*/
const char *current_prefix;
/* A flag to indicate if this is the first tag. Used in list of tags
* for summary.
*/
notmuch_bool_t first_tag;
};
static void
text_string (struct sprinter *sp, const char *val)
{
struct sprinter_text *sptxt = (struct sprinter_text *) sp;
if (sptxt->current_prefix != NULL)
fprintf (sptxt->stream, "%s:", sptxt->current_prefix);
fputs(val, sptxt->stream);
}
static void
text_integer (struct sprinter *sp, int val)
{
struct sprinter_text *sptxt = (struct sprinter_text *) sp;
fprintf (sptxt->stream, "%d", val);
}
static void
text_boolean (struct sprinter *sp, notmuch_bool_t val)
{
struct sprinter_text *sptxt = (struct sprinter_text *) sp;
fputs (val ? "true" : "false", sptxt->stream);
}
static void
text_separator (struct sprinter *sp)
{
struct sprinter_text *sptxt = (struct sprinter_text *) sp;
fputc ('\n', sptxt->stream);
}
static void
text_set_prefix (struct sprinter *sp, const char *prefix)
{
struct sprinter_text *sptxt = (struct sprinter_text *) sp;
sptxt->current_prefix = prefix;
}
/* The structure functions begin_map, begin_list, end and map_key
* don't do anything in the text formatter.
*/
static void
text_begin_map (unused (struct sprinter *sp))
{
}
static void
text_begin_list (unused (struct sprinter *sp))
{
}
static void
text_end (unused (struct sprinter *sp))
{
}
static void
text_null (unused (struct sprinter *sp))
{
}
static void
text_map_key (unused (struct sprinter *sp), unused (const char *key))
{
}
struct sprinter *
sprinter_text_create (const void *ctx, FILE *stream)
{
static const struct sprinter_text template = {
.vtable = {
.begin_map = text_begin_map,
.begin_list = text_begin_list,
.end = text_end,
.string = text_string,
.integer = text_integer,
.boolean = text_boolean,
.null = text_null,
.map_key = text_map_key,
.separator = text_separator,
.set_prefix = text_set_prefix,
.is_text_printer = TRUE,
},
};
struct sprinter_text *res;
res = talloc (ctx, struct sprinter_text);
if (! res)
return NULL;
*res = template;
res->stream = stream;
return &res->vtable;
}

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@ -55,4 +55,14 @@ typedef struct sprinter {
notmuch_bool_t is_text_printer;
} sprinter_t;
/* Create a new unstructured printer that emits the default text format
* for "notmuch search". */
struct sprinter *
sprinter_text_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