core: stream: add utf-8 awareness to b_stream interface

b_stream can now read/write utf-8 encoded data, and will do so unless
the stream is in binary mode.

b_stream will also report an error it encounters invalid utf-8 data
(unless binary mode is enabled).

core/include/blue/core/stream.h

@@ -1,6 +1,7 @@
 #ifndef BLUE_CORE_STREAM_H_
 #define BLUE_CORE_STREAM_H_
 
+#include <blue/core/encoding.h>
 #include <blue/core/macros.h>
 #include <blue/core/misc.h>
 #include <blue/core/status.h>
@@ -40,7 +41,7 @@ B_TYPE_CLASS_DECLARATION_BEGIN(b_stream)
 	b_status (*s_close)(b_stream *);
 	b_status (*s_seek)(b_stream *, long long, b_stream_seek_origin);
 	b_status (*s_tell)(const b_stream *, size_t *);
-	b_status (*s_getc)(b_stream *, int *);
+	b_status (*s_getc)(b_stream *, b_wchar *);
 	b_status (*s_read)(b_stream *, unsigned char *, size_t, size_t *);
 	b_status (*s_write)(b_stream *, const unsigned char *, size_t, size_t *);
 	b_status (*s_reserve)(b_stream *, size_t);
@@ -69,7 +70,7 @@ BLUE_API size_t b_stream_cursor(const b_stream *stream);
 BLUE_API b_status b_stream_push_indent(b_stream *stream, int indent);
 BLUE_API b_status b_stream_pop_indent(b_stream *stream);
 
-BLUE_API b_status b_stream_read_char(b_stream *stream, int *c);
+BLUE_API b_status b_stream_read_char(b_stream *stream, b_wchar *c);
 
 BLUE_API b_status b_stream_read_bytes(
 	b_stream *stream, void *buf, size_t count, size_t *nr_read);
@@ -82,7 +83,7 @@ BLUE_API b_status b_stream_read_all_bytes(
 BLUE_API b_status b_stream_read_all_bytes_s(
 	b_stream *src, b_stream *dest, b_stream_buffer *buffer, size_t *nr_read);
 
-BLUE_API b_status b_stream_write_char(b_stream *stream, char c);
+BLUE_API b_status b_stream_write_char(b_stream *stream, b_wchar c);
 BLUE_API b_status b_stream_write_string(
 	b_stream *stream, const char *s, size_t *nr_written);
 

core/stream.c

@@ -155,7 +155,67 @@ static enum b_status stream_reserve(struct stream_data *stream, size_t len)
 	return stream->s_ops->s_reserve(stream->s_obj, len);
 }
 
-static enum b_status stream_read_char(struct stream_data *stream, int *c)
+static enum b_status read_char_binary(struct stream_data *stream, b_wchar *c)
+{
+	size_t r;
+	unsigned char v = 0;
+	enum b_status status = stream->s_ops->s_read(stream->s_obj, &v, 1, &r);
+
+	*c = v;
+
+	if (status == B_SUCCESS && r < 1) {
+		status = B_ERR_NO_DATA;
+	}
+
+	return status;
+}
+
+static enum b_status read_char_utf8(struct stream_data *stream, b_wchar *c)
+{
+	size_t r;
+	unsigned char s[4];
+	unsigned int len = 0;
+	enum b_status status = stream->s_ops->s_read(stream->s_obj, s, 1, &r);
+
+	if (!B_OK(status)) {
+		return status;
+	}
+
+	if (r < 1) {
+		return B_ERR_NO_DATA;
+	}
+
+	len = b_wchar_utf8_header_decode(s[0]);
+	if (len <= 0 || len > 4) {
+		return B_ERR_BAD_FORMAT;
+	}
+
+	if (len == 1) {
+		*c = s[0];
+		return B_SUCCESS;
+	}
+
+	status = stream->s_ops->s_read(stream->s_obj, s + 1, len - 1, &r);
+
+	if (!B_OK(status)) {
+		return status;
+	}
+
+	if (r != len - 1) {
+		return B_ERR_BAD_FORMAT;
+	}
+
+	b_wchar result = b_wchar_utf8_codepoint_decode((char *)s);
+
+	if (result == B_WCHAR_INVALID) {
+		return B_ERR_BAD_FORMAT;
+	}
+
+	*c = result;
+	return B_SUCCESS;
+}
+
+static enum b_status stream_read_char(struct stream_data *stream, b_wchar *c)
 {
 	if (!(stream->s_cfg->s_mode & B_STREAM_READ)) {
 		return B_ERR_NOT_SUPPORTED;
@@ -163,37 +223,53 @@ static enum b_status stream_read_char(struct stream_data *stream, int *c)
 
 	enum b_status status = B_ERR_NOT_SUPPORTED;
 
+#if 0
 	if (stream->s_ops->s_getc) {
-		status = stream->s_ops->s_getc(stream->s_obj, c);
+		return stream->s_ops->s_getc(stream->s_obj, c);
-	} else if (stream->s_ops->s_read) {
-		size_t r;
-		unsigned char v = 0;
-		status = stream->s_ops->s_read(stream->s_obj, &v, 1, &r);
-
-		*c = v;
-
-		if (status == B_SUCCESS && r < 1) {
-			status = B_ERR_NO_DATA;
 	}
+#endif
+
+	if (!stream->s_ops->s_read) {
+		return B_ERR_NOT_SUPPORTED;
 	}
 
-	return status;
+	if (stream->s_cfg->s_mode & B_STREAM_BINARY) {
+		return read_char_binary(stream, c);
+	}
+
+	return read_char_utf8(stream, c);
 }
 
-static enum b_status __write_char(struct stream_data *stream, char c)
+static enum b_status __write_char(struct stream_data *stream, b_wchar c)
 {
-	size_t w;
+	size_t w, len;
-	enum b_status status = stream->s_ops->s_write(
+	enum b_status status;
-		stream->s_obj, (unsigned char *)&c, 1, &w);
+	char s[4];
 
-	if (status == B_SUCCESS && w < 1) {
+	if (stream->s_cfg->s_mode & B_STREAM_BINARY) {
+		s[0] = c & 0xFF;
+		len = 1;
+	} else {
+		len = b_wchar_utf8_codepoint_encode(c, s);
+		if (len == 0 || len > 4) {
+			return B_ERR_INVALID_ARGUMENT;
+		}
+	}
+
+	status = stream->s_ops->s_write(stream->s_obj, (unsigned char *)s, len, &w);
+
+	if (!B_OK(status)) {
+		return status;
+	}
+
+	if (status == B_SUCCESS && w < len) {
 		status = B_ERR_IO_FAILURE;
 	}
 
 	return status;
 }
 
-static enum b_status stream_write_char(struct stream_data *stream, char c)
+static enum b_status stream_write_char(struct stream_data *stream, b_wchar c)
 {
 	if (!(stream->s_cfg->s_mode & B_STREAM_WRITE)) {
 		return B_ERR_NOT_SUPPORTED;
@@ -257,7 +333,7 @@ static enum b_status stream_read_line(struct stream_data *stream, char *s, size_
 	enum b_status status = B_SUCCESS;
 
 	size_t i = 0;
-	int c = 0;
+	b_wchar c = 0;
 
 	while (1) {
 		if (i >= max) {
@@ -294,7 +370,7 @@ static enum b_status stream_read_line_s(
 	enum b_status status = B_SUCCESS;
 
 	size_t i = 0;
-	int c = 0;
+	b_wchar c = 0;
 
 	while (1) {
 		status = stream_read_char(src, &c);
@@ -698,7 +774,7 @@ enum b_status b_stream_read_all_bytes_s(
 	return stream_read_all_bytes_s(&src_p, &dest_p, buffer_p, out_nr_read);
 }
 
-enum b_status b_stream_write_char(b_stream *stream, char c)
+enum b_status b_stream_write_char(b_stream *stream, b_wchar c)
 {
 	STREAM_DISPATCH_VIRTUAL(stream_write_char, stream, c);
 }