text_input_stream: input_stream wrapper for reading text files

Makefile.am

@@ -88,6 +88,7 @@ mpd_headers = \
 	src/input/curl_input_plugin.h \
 	src/input/lastfm_input_plugin.h \
 	src/input/mms_input_plugin.h \
+	src/text_input_stream.h \
 	src/icy_server.h \
 	src/icy_metadata.h \
 	src/client.h \
@@ -271,6 +272,7 @@ src_mpd_SOURCES = \
 	src/tag_print.c \
 	src/tag_save.c \
 	src/tokenizer.c \
+	src/text_input_stream.c \
 	src/strset.c \
 	src/uri.c \
 	src/utils.c \

src/text_input_stream.c

@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "text_input_stream.h"
+#include "input_stream.h"
+#include "fifo_buffer.h"
+
+#include <glib.h>
+
+#include <string.h>
+
+struct text_input_stream {
+	struct input_stream *is;
+
+	struct fifo_buffer *buffer;
+
+	char *line;
+};
+
+struct text_input_stream *
+text_input_stream_new(struct input_stream *is)
+{
+	struct text_input_stream *tis = g_new(struct text_input_stream, 1);
+
+	tis->is = is;
+	tis->buffer = fifo_buffer_new(4096);
+	tis->line = NULL;
+
+	return tis;
+}
+
+void
+text_input_stream_free(struct text_input_stream *tis)
+{
+	fifo_buffer_free(tis->buffer);
+	g_free(tis->line);
+	g_free(tis);
+}
+
+const char *
+text_input_stream_read(struct text_input_stream *tis)
+{
+	void *dest;
+	const char *src, *p;
+	size_t length, nbytes;
+
+	g_free(tis->line);
+	tis->line = NULL;
+
+	do {
+		dest = fifo_buffer_write(tis->buffer, &length);
+		if (dest != NULL) {
+			nbytes = input_stream_read(tis->is, dest, length);
+			if (nbytes > 0)
+				fifo_buffer_append(tis->buffer, nbytes);
+		}
+
+		src = fifo_buffer_read(tis->buffer, &length);
+		if (src == NULL)
+			return NULL;
+
+		p = memchr(src, '\n', length);
+	} while (p == NULL);
+
+	length = p - src + 1;
+	while (p > src && g_ascii_isspace(p[-1]))
+		--p;
+
+	tis->line = g_strndup(src, p - src);
+	fifo_buffer_consume(tis->buffer, length);
+	return tis->line;
+}

src/text_input_stream.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_TEXT_INPUT_STREAM_H
+#define MPD_TEXT_INPUT_STREAM_H
+
+struct input_stream;
+struct text_input_stream;
+
+/**
+ * Wraps an existing #input_stream object into a #text_input_stream,
+ * to read its contents as text lines.
+ *
+ * @param is an open #input_stream object
+ * @return the new #text_input_stream object
+ */
+struct text_input_stream *
+text_input_stream_new(struct input_stream *is);
+
+/**
+ * Frees the #text_input_stream object.  Does not close or free the
+ * underlying #input_stream.
+ */
+void
+text_input_stream_free(struct text_input_stream *tis);
+
+/**
+ * Reads the next line from the stream.
+ *
+ * @return a line (newline character stripped), or NULL on end of file
+ * or error
+ */
+const char *
+text_input_stream_read(struct text_input_stream *tis);
+
+#endif