core: stringstream: added read-support

any characters written to a stringstream can be optionally read back again
using the b_stream read API.

this functions similar to a ringbuffer, with two key differences:
 1) the buffer is not circular, and will continuously expand to accomodate all incoming data.
 2) reading data from the stringstream does not remove it from the buffer.

core/include/blue/core/stringstream.h

@@ -30,20 +30,6 @@ BLUE_API char *b_stringstream_steal(b_stringstream *strv);
 
 BLUE_API size_t b_stringstream_get_length(const b_stringstream *strv);
 
-#if 0
-BLUE_API void b_stringstream_push_indent(b_stringstream *strv, int indent);
-BLUE_API void b_stringstream_pop_indent(b_stringstream *strv);
-
-BLUE_API b_status b_stringstream_add(b_stringstream *strv, const char *str);
-BLUE_API b_status b_stringstream_addf(b_stringstream *strv, const char *format, ...);
-BLUE_API b_status b_stringstream_addv(b_stringstream *strv, const char **strs);
-BLUE_API b_status b_stringstream_addvf(
-	b_stringstream *strv, const char *format, va_list arg);
-BLUE_API b_status b_stringstream_addvl(
-	b_stringstream *strv, const char **strs, size_t count);
-BLUE_API b_status b_stringstream_add_many(b_stringstream *strv, ...);
-#endif
-
 B_DECLS_END;
 
 #endif

core/stringstream.c

@@ -10,6 +10,7 @@
 
 struct b_stringstream_p {
 	char *ss_buf;
+	size_t ss_ptr;
 	size_t ss_len;
 	size_t ss_max;
 	unsigned char ss_alloc;
@@ -17,6 +18,50 @@ struct b_stringstream_p {
 
 /*** PRIVATE FUNCTIONS ********************************************************/
 
+static enum b_status __getc(struct b_stringstream_p *ss, b_wchar *out)
+{
+	size_t available = ss->ss_len - ss->ss_ptr;
+
+	const char *p = ss->ss_buf + ss->ss_ptr;
+
+	size_t to_copy = b_wchar_utf8_codepoint_stride(p);
+	if (to_copy > available) {
+		return B_ERR_BAD_STATE;
+	}
+
+	b_wchar c = b_wchar_utf8_codepoint_decode(p);
+	*out = c;
+
+	if (c == B_WCHAR_INVALID) {
+		return B_ERR_BAD_STATE;
+	}
+
+	ss->ss_ptr += to_copy;
+
+	return B_SUCCESS;
+}
+
+static enum b_status __gets(
+	struct b_stringstream_p *ss, char *s, size_t len, size_t *nr_read)
+{
+	size_t available = ss->ss_len - ss->ss_ptr;
+	size_t to_copy = len;
+
+	if (available < to_copy) {
+		to_copy = available;
+	}
+
+	memcpy(s, ss->ss_buf + ss->ss_ptr, to_copy);
+
+	ss->ss_ptr += to_copy;
+
+	if (nr_read) {
+		*nr_read = to_copy;
+	}
+
+	return B_SUCCESS;
+}
+
 static enum b_status __puts(
 	struct b_stringstream_p *ss, const char *s, size_t len, size_t *nr_written)
 {
@@ -111,7 +156,7 @@ b_stringstream *b_stringstream_create_with_buffer(char *buf, size_t max)
 	b_stream_cfg *cfg = b_object_get_protected(s, B_TYPE_STREAM);
 	struct b_stringstream_p *p = b_object_get_private(s, B_TYPE_STRINGSTREAM);
 
-	cfg->s_mode = B_STREAM_WRITE | Z__B_STREAM_STATIC;
+	cfg->s_mode = B_STREAM_READ | B_STREAM_WRITE | Z__B_STREAM_STATIC;
 
 	p->ss_buf = buf;
 	p->ss_max = max;
@@ -131,7 +176,7 @@ b_stringstream *b_stringstream_create(void)
 	b_stream_cfg *cfg = b_object_get_protected(s, B_TYPE_STREAM);
 	struct b_stringstream_p *p = b_object_get_private(s, B_TYPE_STRINGSTREAM);
 
-	cfg->s_mode = B_STREAM_WRITE | Z__B_STREAM_STATIC;
+	cfg->s_mode = B_STREAM_READ | B_STREAM_WRITE | Z__B_STREAM_STATIC;
 
 	p->ss_buf = malloc(DEFAULT_CAPACITY + 1);
 	if (!p->ss_buf) {
@@ -193,6 +238,26 @@ static void stringstream_fini(b_object *obj, void *priv)
 	}
 }
 
+enum b_status stream_getc(b_stream *stream, b_wchar *c)
+{
+	struct b_stringstream_p *s
+		= b_object_get_private(stream, B_TYPE_STRINGSTREAM);
+
+	enum b_status status = __getc(s, c);
+
+	return status;
+}
+
+enum b_status stream_read(b_stream *stream, void *buf, size_t count, size_t *nr_read)
+{
+	struct b_stringstream_p *s
+		= b_object_get_private(stream, B_TYPE_STRINGSTREAM);
+
+	enum b_status status = __gets(s, buf, count, nr_read);
+
+	return status;
+}
+
 enum b_status stream_write(
 	b_stream *stream, const void *buf, size_t count, size_t *nr_written)
 {
@@ -215,8 +280,8 @@ B_TYPE_CLASS_DEFINITION_BEGIN(b_stringstream)
 		B_INTERFACE_ENTRY(s_close) = NULL;
 		B_INTERFACE_ENTRY(s_seek) = NULL;
 		B_INTERFACE_ENTRY(s_tell) = NULL;
-		B_INTERFACE_ENTRY(s_getc) = NULL;
+		B_INTERFACE_ENTRY(s_getc) = stream_getc;
-		B_INTERFACE_ENTRY(s_read) = NULL;
+		B_INTERFACE_ENTRY(s_read) = stream_read;
 		B_INTERFACE_ENTRY(s_write) = stream_write;
 		B_INTERFACE_ENTRY(s_reserve) = NULL;
 	B_TYPE_CLASS_INTERFACE_END(b_stream, B_TYPE_STREAM)