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/*
* Copyright (C) 2003-2015 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 "config.h"
#include "IcyMetaDataParser.hxx"
#include "tag/Tag.hxx"
#include "tag/TagBuilder.hxx"
#include "util/Domain.hxx"
#include "Log.hxx"
#include <assert.h>
#include <string.h>
static constexpr Domain icy_metadata_domain("icy_metadata");
void
IcyMetaDataParser::Reset()
{
if (!IsDefined())
return;
if (data_rest == 0 && meta_size > 0)
delete[] meta_data;
delete tag;
data_rest = data_size;
meta_size = 0;
}
size_t
IcyMetaDataParser::Data(size_t length)
{
assert(length > 0);
if (!IsDefined())
return length;
if (data_rest == 0)
return 0;
if (length >= data_rest) {
length = data_rest;
data_rest = 0;
} else
data_rest -= length;
return length;
}
static void
icy_add_item(TagBuilder &tag, TagType type, const char *value)
{
size_t length = strlen(value);
if (length >= 2 && value[0] == '\'' && value[length - 1] == '\'') {
/* strip the single quotes */
++value;
length -= 2;
}
if (length > 0)
tag.AddItem(type, value, length);
}
static void
icy_parse_tag_item(TagBuilder &tag, const char *name, const char *value)
{
if (strcmp(name, "StreamTitle") == 0)
icy_add_item(tag, TAG_TITLE, value);
else
FormatDebug(icy_metadata_domain,
"unknown icy-tag: '%s'", name);
}
/**
* Find a single quote that is followed by a semicolon (or by the end
* of the string). If that fails, return the first single quote. If
* that also fails, return #end.
*/
static char *
find_end_quote(char *p, char *const end)
{
char *fallback = std::find(p, end, '\'');
if (fallback >= end - 1 || fallback[1] == ';')
return fallback;
p = fallback + 1;
while (true) {
p = std::find(p, end, '\'');
if (p == end)
return fallback;
if (p == end - 1 || p[1] == ';')
return p;
++p;
}
}
static Tag *
icy_parse_tag(char *p, char *const end)
{
assert(p != nullptr);
assert(end != nullptr);
assert(p <= end);
TagBuilder tag;
while (p != end) {
const char *const name = p;
char *eq = std::find(p, end, '=');
if (eq == end)
break;
*eq = 0;
p = eq + 1;
if (*p != '\'') {
/* syntax error; skip to the next semicolon,
try to recover */
char *semicolon = std::find(p, end, ';');
if (semicolon == end)
break;
p = semicolon + 1;
continue;
}
++p;
const char *const value = p;
char *quote = find_end_quote(p, end);
if (quote == end)
break;
*quote = 0;
p = quote + 1;
icy_parse_tag_item(tag, name, value);
char *semicolon = std::find(p, end, ';');
if (semicolon == end)
break;
p = semicolon + 1;
}
return tag.CommitNew();
}
size_t
IcyMetaDataParser::Meta(const void *data, size_t length)
{
const unsigned char *p = (const unsigned char *)data;
assert(IsDefined());
assert(data_rest == 0);
assert(length > 0);
if (meta_size == 0) {
/* read meta_size from the first byte of a meta
block */
meta_size = *p++ * 16;
if (meta_size == 0) {
/* special case: no metadata */
data_rest = data_size;
return 1;
}
/* 1 byte was consumed (must be re-added later for the
return value */
--length;
/* initialize metadata reader, allocate enough
memory (+1 for the null terminator) */
meta_position = 0;
meta_data = new char[meta_size + 1];
}
assert(meta_position < meta_size);
if (length > meta_size - meta_position)
length = meta_size - meta_position;
memcpy(meta_data + meta_position, p, length);
meta_position += length;
if (p != data)
/* re-add the first byte (which contained meta_size) */
++length;
if (meta_position == meta_size) {
/* parse */
delete tag;
tag = icy_parse_tag(meta_data, meta_data + meta_size);
delete[] meta_data;
/* change back to normal data mode */
meta_size = 0;
data_rest = data_size;
}
return length;
}
size_t
IcyMetaDataParser::ParseInPlace(void *data, size_t length)
{
uint8_t *const dest0 = (uint8_t *)data;
uint8_t *dest = dest0;
const uint8_t *src = dest0;
while (length > 0) {
size_t chunk = Data(length);
if (chunk > 0) {
memmove(dest, src, chunk);
dest += chunk;
src += chunk;
length -= chunk;
if (length == 0)
break;
}
chunk = Meta(src, length);
if (chunk > 0) {
src += chunk;
length -= chunk;
}
}
return dest - dest0;
}
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