blob: bb3717f94aa0f4a95bc470ed921f857557e5e018 [file] [log] [blame]
/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <media/mediascanner.h>
#include <utils/StringArray.h>
#include "autodetect.h"
#include "unicode/ucnv.h"
#include "unicode/ustring.h"
namespace android {
MediaScannerClient::MediaScannerClient()
: mNames(NULL),
mValues(NULL),
mLocaleEncoding(kEncodingNone)
{
}
MediaScannerClient::~MediaScannerClient()
{
delete mNames;
delete mValues;
}
void MediaScannerClient::setLocale(const char* locale)
{
if (!locale) return;
if (!strncmp(locale, "ja", 2))
mLocaleEncoding = kEncodingShiftJIS;
else if (!strncmp(locale, "ko", 2))
mLocaleEncoding = kEncodingEUCKR;
else if (!strncmp(locale, "zh", 2)) {
if (!strcmp(locale, "zh_CN")) {
// simplified chinese for mainland China
mLocaleEncoding = kEncodingGBK;
} else {
// assume traditional for non-mainland Chinese locales (Taiwan, Hong Kong, Singapore)
mLocaleEncoding = kEncodingBig5;
}
}
}
void MediaScannerClient::beginFile()
{
mNames = new StringArray;
mValues = new StringArray;
}
bool MediaScannerClient::addStringTag(const char* name, const char* value)
{
// don't bother caching strings that are all ASCII.
// call handleStringTag directly instead.
// check to see if value (which should be utf8) has any non-ASCII characters
bool nonAscii = false;
const char* chp = value;
char ch;
while ((ch = *chp++)) {
if (ch & 0x80) {
nonAscii = true;
break;
}
}
if (nonAscii) {
// save the strings for later so they can be used for native encoding detection
mNames->push_back(name);
mValues->push_back(value);
return true;
}
// else fall through
// autodetection is not necessary, so no need to cache the values
// pass directly to the client instead
return handleStringTag(name, value);
}
static uint32_t possibleEncodings(const char* s)
{
uint32_t result = kEncodingAll;
// if s contains a native encoding, then it was mistakenly encoded in utf8 as if it were latin-1
// so we need to reverse the latin-1 -> utf8 conversion to get the native chars back
uint8_t ch1, ch2;
uint8_t* chp = (uint8_t *)s;
while ((ch1 = *chp++)) {
if (ch1 & 0x80) {
ch2 = *chp++;
ch1 = ((ch1 << 6) & 0xC0) | (ch2 & 0x3F);
// ch1 is now the first byte of the potential native char
ch2 = *chp++;
if (ch2 & 0x80)
ch2 = ((ch2 << 6) & 0xC0) | (*chp++ & 0x3F);
// ch2 is now the second byte of the potential native char
int ch = (int)ch1 << 8 | (int)ch2;
result &= findPossibleEncodings(ch);
}
// else ASCII character, which could be anything
}
return result;
}
void MediaScannerClient::convertValues(uint32_t encoding)
{
const char* enc = NULL;
switch (encoding) {
case kEncodingShiftJIS:
enc = "shift-jis";
break;
case kEncodingGBK:
enc = "gbk";
break;
case kEncodingBig5:
enc = "Big5";
break;
case kEncodingEUCKR:
enc = "EUC-KR";
break;
}
if (enc) {
UErrorCode status = U_ZERO_ERROR;
UConverter *conv = ucnv_open(enc, &status);
if (U_FAILURE(status)) {
LOGE("could not create UConverter for %s\n", enc);
return;
}
UConverter *utf8Conv = ucnv_open("UTF-8", &status);
if (U_FAILURE(status)) {
LOGE("could not create UConverter for UTF-8\n");
ucnv_close(conv);
return;
}
// for each value string, convert from native encoding to UTF-8
for (int i = 0; i < mNames->size(); i++) {
// first we need to untangle the utf8 and convert it back to the original bytes
// since we are reducing the length of the string, we can do this in place
uint8_t* src = (uint8_t *)mValues->getEntry(i);
int len = strlen((char *)src);
uint8_t* dest = src;
uint8_t uch;
while ((uch = *src++)) {
if (uch & 0x80)
*dest++ = ((uch << 6) & 0xC0) | (*src++ & 0x3F);
else
*dest++ = uch;
}
*dest = 0;
// now convert from native encoding to UTF-8
const char* source = mValues->getEntry(i);
int targetLength = len * 3 + 1;
char* buffer = new char[targetLength];
if (!buffer)
break;
char* target = buffer;
ucnv_convertEx(utf8Conv, conv, &target, target + targetLength,
&source, (const char *)dest, NULL, NULL, NULL, NULL, TRUE, TRUE, &status);
if (U_FAILURE(status)) {
LOGE("ucnv_convertEx failed: %d\n", status);
mValues->setEntry(i, "???");
} else {
// zero terminate
*target = 0;
mValues->setEntry(i, buffer);
}
delete[] buffer;
}
ucnv_close(conv);
ucnv_close(utf8Conv);
}
}
void MediaScannerClient::endFile()
{
int size = mNames->size();
uint32_t encoding = kEncodingAll;
// compute a bit mask containing all possible encodings
for (int i = 0; i < mNames->size(); i++)
encoding &= possibleEncodings(mValues->getEntry(i));
// If one of the possible encodings matches the locale encoding, use that.
// Otherwise, if there is only one possible encoding, use that.
if (encoding & mLocaleEncoding)
convertValues(mLocaleEncoding);
else if ((encoding & (encoding - 1)) == 0)
convertValues(encoding);
else {
// TODO: try harder to disambiguate the encoding, perhaps by looking at
// other files by same artist, or even the user's entire collection.
// For now, fall through and insert the strings as they are.
}
// finally, push all name/value pairs to the client
for (int i = 0; i < mNames->size(); i++) {
if (!handleStringTag(mNames->getEntry(i), mValues->getEntry(i)))
break;
}
// else addStringTag() has done all the work so we have nothing to do
delete mNames;
delete mValues;
mNames = NULL;
mValues = NULL;
}
} // namespace android