Code deduplication: move mod_loadfile() into ModCommon.cxx

src/decoder/plugins/ModCommon.cxx

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2003-2021 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 "ModCommon.hxx"
+#include "Log.hxx"
+
+static constexpr size_t MOD_PREALLOC_BLOCK = 256 * 1024;
+static constexpr offset_type MOD_FILE_LIMIT = 100 * 1024 * 1024;
+
+WritableBuffer<uint8_t>
+mod_loadfile(const Domain *domain, DecoderClient *client, InputStream &is)
+{
+	//known/unknown size, preallocate array, lets read in chunks
+
+	const bool is_stream = !is.KnownSize();
+
+	WritableBuffer<uint8_t> buffer;
+	if (is_stream)
+		buffer.size = MOD_PREALLOC_BLOCK;
+	else {
+		const auto size = is.GetSize();
+
+		if (size == 0) {
+			LogWarning(*domain, "file is empty");
+			return nullptr;
+		}
+
+		if (size > MOD_FILE_LIMIT) {
+			LogWarning(*domain, "file too large");
+			return nullptr;
+		}
+
+		buffer.size = size;
+	}
+
+	buffer.data = new uint8_t[buffer.size];
+
+	uint8_t *const end = buffer.end();
+	uint8_t *p = buffer.begin();
+
+	while (true) {
+		size_t ret = decoder_read(client, is, p, end - p);
+		if (ret == 0) {
+			if (is.LockIsEOF())
+				/* end of file */
+				break;
+
+			/* I/O error - skip this song */
+			delete[] buffer.data;
+			buffer.data = nullptr;
+			return buffer;
+		}
+
+		p += ret;
+		if (p == end) {
+			if (!is_stream)
+				break;
+
+			LogWarning(*domain, "stream too large");
+			delete[] buffer.data;
+			buffer.data = nullptr;
+			return buffer;
+		}
+	}
+
+	buffer.size = p - buffer.data;
+	return buffer;
+}
+