From: Austin Clements <amdragon@MIT.EDU>
To: notmuch@notmuchmail.org
Subject: [PATCH 03/13] sprinter: Add a string_len method
Date: Tue, 24 Jul 2012 22:34:43 -0400
Message-Id: <1343183693-17134-4-git-send-email-amdragon@mit.edu>
In-Reply-To: <1343183693-17134-1-git-send-email-amdragon@mit.edu>
References: <1343183693-17134-1-git-send-email-amdragon@mit.edu>
Precedence: list

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.
---
 sprinter-json.c |   11 +++++++++--
 sprinter-text.c |   11 +++++++++--
 sprinter.h      |    1 +
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/sprinter-json.c b/sprinter-json.c
index 4649655..2587ca6 100644
--- a/sprinter-json.c
+++ b/sprinter-json.c
@@ -89,7 +89,7 @@ json_end (struct sprinter *sp)
 }
 
 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 +98,7 @@ 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);
@@ -111,6 +111,12 @@ json_string (struct sprinter *sp, const char *val)
 }
 
 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)
 {
     struct sprinter_json *spj = json_begin_value (sp);
@@ -166,6 +172,7 @@ 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,
diff --git a/sprinter-text.c b/sprinter-text.c
index b208840..dfa54b5 100644
--- a/sprinter-text.c
+++ b/sprinter-text.c
@@ -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,
diff --git a/sprinter.h b/sprinter.h
index 6680d41..826a852 100644
--- a/sprinter.h
+++ b/sprinter.h
@@ -28,6 +28,7 @@ typedef struct sprinter {
      * For string, the char * must be UTF-8 encoded.
      */
     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 *);
-- 
1.7.10