sprinter: Add a string_len method

This method allows callers to output strings with specific lengths.
It's useful both for strings with embedded NULs (which JSON can
represent, though parser support is apparently spotty), and
non-terminated strings.
This commit is contained in:
Austin Clements 2012-08-02 21:14:49 -04:00 committed by David Bremner
parent 624d1897ce
commit 14883b0700
3 changed files with 29 additions and 7 deletions

View file

@ -88,8 +88,13 @@ json_end (struct sprinter *sp)
fputc ('\n', spj->stream);
}
/* This implementation supports embedded NULs as allowed by the JSON
* specification and Unicode. Support for *parsing* embedded NULs
* varies, but is generally not a problem outside of C-based parsers
* (Python's json module and Emacs' json.el take embedded NULs in
* stride). */
static void
json_string (struct sprinter *sp, const char *val)
json_string_len (struct sprinter *sp, const char *val, size_t len)
{
static const char *const escapes[] = {
['\"'] = "\\\"", ['\\'] = "\\\\", ['\b'] = "\\b",
@ -98,7 +103,7 @@ json_string (struct sprinter *sp, const char *val)
struct sprinter_json *spj = json_begin_value (sp);
fputc ('"', spj->stream);
for (; *val; ++val) {
for (; len; ++val, --len) {
unsigned char ch = *val;
if (ch < ARRAY_SIZE (escapes) && escapes[ch])
fputs (escapes[ch], spj->stream);
@ -110,6 +115,12 @@ json_string (struct sprinter *sp, const char *val)
fputc ('"', spj->stream);
}
static void
json_string (struct sprinter *sp, const char *val)
{
json_string_len (sp, val, strlen (val));
}
static void
json_integer (struct sprinter *sp, int val)
{
@ -166,6 +177,7 @@ sprinter_json_create (const void *ctx, FILE *stream)
.begin_list = json_begin_list,
.end = json_end,
.string = json_string,
.string_len = json_string_len,
.integer = json_integer,
.boolean = json_boolean,
.null = json_null,

View file

@ -25,14 +25,20 @@ struct sprinter_text {
};
static void
text_string (struct sprinter *sp, const char *val)
text_string_len (struct sprinter *sp, const char *val, size_t len)
{
struct sprinter_text *sptxt = (struct sprinter_text *) sp;
if (sptxt->current_prefix != NULL)
fprintf (sptxt->stream, "%s:", sptxt->current_prefix);
fputs(val, sptxt->stream);
fwrite (val, len, 1, sptxt->stream);
}
static void
text_string (struct sprinter *sp, const char *val)
{
text_string_len (sp, val, strlen (val));
}
static void
@ -105,6 +111,7 @@ sprinter_text_create (const void *ctx, FILE *stream)
.begin_list = text_begin_list,
.end = text_end,
.string = text_string,
.string_len = text_string_len,
.integer = text_integer,
.boolean = text_boolean,
.null = text_null,

View file

@ -23,11 +23,14 @@ typedef struct sprinter {
*/
void (*end) (struct sprinter *);
/* Print one string/integer/boolean/null element (possibly inside a
* list or map, followed or preceded by separators).
* For string, the char * must be UTF-8 encoded.
/* Print one string/integer/boolean/null element (possibly inside
* a list or map, followed or preceded by separators). For string
* and string_len, the char * must be UTF-8 encoded. string_len
* allows non-terminated strings and strings with embedded NULs
* (though the handling of the latter is format-dependent).
*/
void (*string) (struct sprinter *, const char *);
void (*string_len) (struct sprinter *, const char *, size_t);
void (*integer) (struct sprinter *, int);
void (*boolean) (struct sprinter *, notmuch_bool_t);
void (*null) (struct sprinter *);