Add node constructor and accessors to the public API

The approach I'm taking is to copy inline literals internally to
NULL-terminated C strings if requested by an accessor. This allows to
return a 'const char *' that doesn't have to be freed by the caller.

1 files changed, 28 insertions, 11 deletions

diff --git a/src/chunk.h b/src/chunk.h
index 9dd56b6..7a1dbc3 100644
--- a/src/chunk.h
+++ b/src/chunk.h
@@ -8,15 +8,15 @@
 #include "buffer.h"
 
 typedef struct {
-	const unsigned char *data;
+	unsigned char *data;
 	int len;
-	int alloc;
+	int alloc;  // also implies a NULL-terminated string
 } cmark_chunk;
 
 static inline void cmark_chunk_free(cmark_chunk *c)
 {
 	if (c->alloc)
-		free((char *)c->data);
+		free(c->data);
 
 	c->data = NULL;
 	c->alloc = 0;
@@ -55,21 +55,38 @@ static inline int cmark_chunk_strchr(cmark_chunk *ch, int c, int offset)
 	return p ? (int)(p - ch->data) : ch->len;
 }
 
-static inline unsigned char *cmark_chunk_to_cstr(cmark_chunk *c)
+static inline const char *cmark_chunk_to_cstr(cmark_chunk *c)
 {
 	unsigned char *str;
 
-	str = (unsigned char *)calloc(c->len + 1, sizeof(*str));
-    if(str != NULL) {
-    	memcpy(str, c->data, c->len);
-	    str[c->len] = 0;
-    }
-	return str;
+	if (c->alloc) {
+		return (char *)c->data;
+	}
+	str = (unsigned char *)malloc(c->len + 1);
+	if(str != NULL) {
+		memcpy(str, c->data, c->len);
+		str[c->len] = 0;
+	}
+	c->data  = str;
+	c->alloc = 1;
+
+	return (char *)str;
+}
+
+static inline void cmark_chunk_set_cstr(cmark_chunk *c, const char *str)
+{
+	if (c->alloc) {
+		free(c->data);
+	}
+	c->len   = strlen(str);
+	c->data  = (unsigned char *)malloc(c->len + 1);
+	c->alloc = 1;
+	memcpy(c->data, str, c->len + 1);
 }
 
 static inline cmark_chunk cmark_chunk_literal(const char *data)
 {
-	cmark_chunk c = {(const unsigned char *)data, data ? strlen(data) : 0, 0};
+	cmark_chunk c = {(unsigned char *)data, data ? strlen(data) : 0, 0};
 	return c;
 }