text_file: allocate line buffers dynamically

Makefile.am

@@ -88,6 +88,7 @@ mpd_headers = \
 	src/input/file_input_plugin.h \
 	src/input/curl_input_plugin.h \
 	src/input/mms_input_plugin.h \
+	src/text_file.h \
 	src/text_input_stream.h \
 	src/icy_server.h \
 	src/icy_metadata.h \
@@ -285,6 +286,7 @@ src_mpd_SOURCES = \
 	src/tag_print.c \
 	src/tag_save.c \
 	src/tokenizer.c \
+	src/text_file.c \
 	src/text_input_stream.c \
 	src/strset.c \
 	src/uri.c \

NEWS

@@ -53,6 +53,7 @@ ver 0.16 (20??/??/??)
 * renamed option "--stdout" to "--stderr"
 * removed options --create-db and --no-create-db
 * state_file: save only if something has changed
+* database: eliminated maximum line length
 * obey $(sysconfdir) for default mpd.conf location
 * build with large file support by default
 * require GLib 2.16

src/database.c

@@ -23,6 +23,7 @@
 #include "song.h"
 #include "path.h"
 #include "stats.h"
+#include "text_file.h"
 #include "config.h"
 
 #include <glib.h>
@@ -256,7 +257,8 @@ db_load(GError **error)
 {
 	FILE *fp = NULL;
 	struct stat st;
-	char buffer[100];
+	GString *buffer = g_string_sized_new(1024);
+	char *line;
 	bool found_charset = false, found_version = false;
 	bool success;
 
@@ -270,50 +272,45 @@ db_load(GError **error)
 		g_set_error(error, db_quark(), errno,
 			    "Failed to open database file \"%s\": %s",
 			    database_path, strerror(errno));
+		g_string_free(buffer, true);
 		return false;
 	}
 
 	/* get initial info */
-	if (!fgets(buffer, sizeof(buffer), fp)) {
-		fclose(fp);
-		g_set_error(error, db_quark(), 0, "Unexpected end of file");
-		return false;
-	}
-
-	g_strchomp(buffer);
-
-	if (0 != strcmp(DIRECTORY_INFO_BEGIN, buffer)) {
+	line = read_text_line(fp, buffer);
+	if (line == NULL || strcmp(DIRECTORY_INFO_BEGIN, line) != 0) {
 		fclose(fp);
 		g_set_error(error, db_quark(), 0, "Database corrupted");
+		g_string_free(buffer, true);
 		return false;
 	}
 
-	while (fgets(buffer, sizeof(buffer), fp) &&
-	       !g_str_has_prefix(buffer, DIRECTORY_INFO_END)) {
-		g_strchomp(buffer);
-
-		if (g_str_has_prefix(buffer, DIRECTORY_MPD_VERSION)) {
+	while ((line = read_text_line(fp, buffer)) != NULL &&
+	       !g_str_has_prefix(line, DIRECTORY_INFO_END)) {
+		if (g_str_has_prefix(line, DIRECTORY_MPD_VERSION)) {
 			if (found_version) {
 				fclose(fp);
 				g_set_error(error, db_quark(), 0,
 					    "Duplicate version line");
+				g_string_free(buffer, true);
 				return false;
 			}
 
 			found_version = true;
-		} else if (g_str_has_prefix(buffer, DIRECTORY_FS_CHARSET)) {
+		} else if (g_str_has_prefix(line, DIRECTORY_FS_CHARSET)) {
 			const char *new_charset, *old_charset;
 
 			if (found_charset) {
 				fclose(fp);
 				g_set_error(error, db_quark(), 0,
 					    "Duplicate charset line");
+				g_string_free(buffer, true);
 				return false;
 			}
 
 			found_charset = true;
 
-			new_charset = &(buffer[strlen(DIRECTORY_FS_CHARSET)]);
+			new_charset = line + sizeof(DIRECTORY_FS_CHARSET) - 1;
 			old_charset = path_get_fs_charset();
 			if (old_charset != NULL
 			    && strcmp(new_charset, old_charset)) {
@@ -323,19 +320,22 @@ db_load(GError **error)
 					    "\"%s\" instead of \"%s\"; "
 					    "discarding database file",
 					    new_charset, old_charset);
+				g_string_free(buffer, true);
 				return false;
 			}
 		} else {
 			fclose(fp);
 			g_set_error(error, db_quark(), 0,
-				    "Malformed line: %s", buffer);
+				    "Malformed line: %s", line);
+			g_string_free(buffer, true);
 			return false;
 		}
 	}
 
 	g_debug("reading DB");
 
-	success = directory_load(fp, music_root, error);
+	success = directory_load(fp, music_root, buffer, error);
+	g_string_free(buffer, true);
 	while (fclose(fp) && errno == EINTR) ;
 
 	if (!success)

src/directory_save.c

@@ -20,7 +20,7 @@
 #include "directory_save.h"
 #include "directory.h"
 #include "song.h"
-#include "path.h"
+#include "text_file.h"
 #include "song_save.h"
 
 #include <assert.h>
@@ -80,10 +80,10 @@ directory_save(FILE *fp, struct directory *directory)
 
 static struct directory *
 directory_load_subdir(FILE *fp, struct directory *parent, const char *name,
-		      GError **error_r)
+		      GString *buffer, GError **error_r)
 {
-	char buffer[MPD_PATH_MAX * 2];
 	struct directory *directory;
+	const char *line;
 	bool success;
 
 	if (directory_get_child(parent, name) != NULL) {
@@ -101,19 +101,21 @@ directory_load_subdir(FILE *fp, struct directory *parent, const char *name,
 		g_free(path);
 	}
 
-	if (!fgets(buffer, sizeof(buffer), fp)) {
+	line = read_text_line(fp, buffer);
+	if (line == NULL) {
 		g_set_error(error_r, directory_quark(), 0,
 			    "Unexpected end of file");
 		directory_free(directory);
 		return NULL;
 	}
 
-	if (g_str_has_prefix(buffer, DIRECTORY_MTIME)) {
+	if (g_str_has_prefix(line, DIRECTORY_MTIME)) {
 		directory->mtime =
-			g_ascii_strtoull(buffer + sizeof(DIRECTORY_MTIME) - 1,
+			g_ascii_strtoull(line + sizeof(DIRECTORY_MTIME) - 1,
 					 NULL, 10);
 
-		if (!fgets(buffer, sizeof(buffer), fp)) {
+		line = read_text_line(fp, buffer);
+		if (line == NULL) {
 			g_set_error(error_r, directory_quark(), 0,
 				    "Unexpected end of file");
 			directory_free(directory);
@@ -121,14 +123,14 @@ directory_load_subdir(FILE *fp, struct directory *parent, const char *name,
 		}
 	}
 
-	if (!g_str_has_prefix(buffer, DIRECTORY_BEGIN)) {
+	if (!g_str_has_prefix(line, DIRECTORY_BEGIN)) {
 		g_set_error(error_r, directory_quark(), 0,
-			    "Malformed line: %s", buffer);
+			    "Malformed line: %s", line);
 		directory_free(directory);
 		return NULL;
 	}
 
-	success = directory_load(fp, directory, error_r);
+	success = directory_load(fp, directory, buffer, error_r);
 	if (!success) {
 		directory_free(directory);
 		return NULL;
@@ -138,32 +140,31 @@ directory_load_subdir(FILE *fp, struct directory *parent, const char *name,
 }
 
 bool
-directory_load(FILE *fp, struct directory *directory, GError **error)
+directory_load(FILE *fp, struct directory *directory,
+	       GString *buffer, GError **error)
 {
-	char buffer[MPD_PATH_MAX * 2];
+	const char *line;
 	bool success;
 
-	while (fgets(buffer, sizeof(buffer), fp)
-	       && !g_str_has_prefix(buffer, DIRECTORY_END)) {
-		g_strchomp(buffer);
-
-		if (g_str_has_prefix(buffer, DIRECTORY_DIR)) {
+	while ((line = read_text_line(fp, buffer)) != NULL &&
+	       !g_str_has_prefix(line, DIRECTORY_END)) {
+		if (g_str_has_prefix(line, DIRECTORY_DIR)) {
 			struct directory *subdir =
 				directory_load_subdir(fp, directory,
-						      buffer + sizeof(DIRECTORY_DIR) - 1,
-						      error);
+						      line + sizeof(DIRECTORY_DIR) - 1,
+						      buffer, error);
 			if (subdir == NULL)
 				return false;
 
 			dirvec_add(&directory->children, subdir);
-		} else if (g_str_has_prefix(buffer, SONG_BEGIN)) {
+		} else if (g_str_has_prefix(line, SONG_BEGIN)) {
 			success = songvec_load(fp, &directory->songs,
-					       directory, error);
+					       directory, buffer, error);
 			if (!success)
 				return false;
 		} else {
 			g_set_error(error, directory_quark(), 0,
-				    "Malformed line: %s", buffer);
+				    "Malformed line: %s", line);
 			return false;
 		}
 	}

src/directory_save.h

@@ -31,6 +31,7 @@ int
 directory_save(FILE *fp, struct directory *directory);
 
 bool
-directory_load(FILE *fp, struct directory *directory, GError **error);
+directory_load(FILE *fp, struct directory *directory,
+	       GString *buffer, GError **error);
 
 #endif

src/song_save.c

@@ -21,8 +21,8 @@
 #include "song.h"
 #include "tag_save.h"
 #include "directory.h"
-#include "path.h"
 #include "tag.h"
+#include "text_file.h"
 
 #include <glib.h>
 
@@ -117,32 +117,31 @@ parse_tag_value(char *buffer, enum tag_type *type_r)
 
 bool
 songvec_load(FILE *fp, struct songvec *sv, struct directory *parent,
-	     GError **error_r)
+	     GString *buffer, GError **error_r)
 {
-	char buffer[MPD_PATH_MAX + 1024];
+	char *line;
 	struct song *song = NULL;
 	enum tag_type type;
 	const char *value;
 
-	while (fgets(buffer, sizeof(buffer), fp) &&
-	       !g_str_has_prefix(buffer, SONG_END)) {
-		g_strchomp(buffer);
+	while ((line = read_text_line(fp, buffer)) != NULL &&
+	       !g_str_has_prefix(line, SONG_END)) {
 
-		if (0 == strncmp(SONG_KEY, buffer, strlen(SONG_KEY))) {
+		if (0 == strncmp(SONG_KEY, line, strlen(SONG_KEY))) {
 			if (song)
 				commit_song(sv, song);
 
-			song = song_file_new(buffer + strlen(SONG_KEY),
+			song = song_file_new(line + strlen(SONG_KEY),
 					     parent);
-		} else if (*buffer == 0) {
+		} else if (*line == 0) {
 			/* ignore empty lines (starting with '\0') */
 		} else if (song == NULL) {
 			g_set_error(error_r, song_save_quark(), 0,
 				    "Problems reading song info");
 			return false;
-		} else if (0 == strncmp(SONG_FILE, buffer, strlen(SONG_FILE))) {
+		} else if (0 == strncmp(SONG_FILE, line, strlen(SONG_FILE))) {
 			/* we don't need this info anymore */
-		} else if ((value = parse_tag_value(buffer,
+		} else if ((value = parse_tag_value(line,
 						    &type)) != NULL) {
 			if (!song->tag) {
 				song->tag = tag_new();
@@ -150,18 +149,18 @@ songvec_load(FILE *fp, struct songvec *sv, struct directory *parent,
 			}
 
 			tag_add_item(song->tag, type, value);
-		} else if (0 == strncmp(SONG_TIME, buffer, strlen(SONG_TIME))) {
+		} else if (0 == strncmp(SONG_TIME, line, strlen(SONG_TIME))) {
 			if (!song->tag) {
 				song->tag = tag_new();
 				tag_begin_add(song->tag);
 			}
 
-			song->tag->time = atoi(&(buffer[strlen(SONG_TIME)]));
-		} else if (0 == strncmp(SONG_MTIME, buffer, strlen(SONG_MTIME))) {
-			song->mtime = atoi(&(buffer[strlen(SONG_MTIME)]));
+			song->tag->time = atoi(&(line[strlen(SONG_TIME)]));
+		} else if (0 == strncmp(SONG_MTIME, line, strlen(SONG_MTIME))) {
+			song->mtime = atoi(&(line[strlen(SONG_MTIME)]));
 		} else {
 			g_set_error(error_r, song_save_quark(), 0,
-				    "unknown line in db: %s", buffer);
+				    "unknown line in db: %s", line);
 			return false;
 		}
 	}

src/song_save.h

@@ -40,6 +40,6 @@ void songvec_save(FILE *fp, struct songvec *sv);
  */
 bool
 songvec_load(FILE *file, struct songvec *sv, struct directory *parent,
-	     GError **error_r);
+	     GString *buffer, GError **error_r);
 
 #endif

src/text_file.c

+/*
+ * 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_file.h"
+
+#include <assert.h>
+#include <string.h>
+
+char *
+read_text_line(FILE *file, GString *buffer)
+{
+	enum {
+		max_length = 512 * 1024,
+		step = 1024,
+	};
+
+	gsize length = 0, i;
+	char *p;
+
+	assert(file != NULL);
+	assert(buffer != NULL);
+
+	if (buffer->allocated_len < step)
+		g_string_set_size(buffer, step);
+
+	while (buffer->len < max_length) {
+		p = fgets(buffer->str + length,
+			  buffer->allocated_len - length, file);
+		if (p == NULL) {
+			if (length == 0 || ferror(file))
+				return NULL;
+			break;
+		}
+
+		i = strlen(buffer->str + length);
+		length += i;
+		if (i < step - 1 || buffer->str[length - 1] == '\n')
+			break;
+
+		g_string_set_size(buffer, length + step);
+	}
+
+	g_string_set_size(buffer, length);
+	g_strchomp(buffer->str);
+	return buffer->str;
+}

src/text_file.h

+/*
+ * 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_FILE_H
+#define MPD_TEXT_FILE_H
+
+#include <glib.h>
+
+#include <stdio.h>
+
+/**
+ * Reads a line from the input file, and strips trailing space.  There
+ * is a reasonable maximum line length, only to prevent denial of
+ * service.
+ *
+ * @param file the source file, opened in text mode
+ * @param buffer an allocator for the buffer
+ * @return a pointer to the line, or NULL on end-of-file or error
+ */
+char *
+read_text_line(FILE *file, GString *buffer);
+
+#endif