blob: c3ec1652b292a04fedda6db7f037113136263408 [file] [log] [blame]
/*
* Copyright (C) 2010 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.
*/
#define LOG_TAG "Tokenizer"
#include <utils/Tokenizer.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <utils/Log.h>
#ifndef DEBUG_TOKENIZER
// Enables debug output for the tokenizer.
#define DEBUG_TOKENIZER 0
#endif
namespace android {
static inline bool isDelimiter(char ch, const char* delimiters) {
return strchr(delimiters, ch) != nullptr;
}
Tokenizer::Tokenizer(const String8& filename, FileMap* fileMap, char* buffer,
bool ownBuffer, size_t length) :
mFilename(filename), mFileMap(fileMap),
mBuffer(buffer), mOwnBuffer(ownBuffer), mLength(length),
mCurrent(buffer), mLineNumber(1) {
}
Tokenizer::~Tokenizer() {
delete mFileMap;
if (mOwnBuffer) {
delete[] mBuffer;
}
}
status_t Tokenizer::open(const String8& filename, Tokenizer** outTokenizer) {
*outTokenizer = nullptr;
int result = OK;
int fd = ::open(filename.string(), O_RDONLY);
if (fd < 0) {
result = -errno;
ALOGE("Error opening file '%s': %s", filename.string(), strerror(errno));
} else {
struct stat stat;
if (fstat(fd, &stat)) {
result = -errno;
ALOGE("Error getting size of file '%s': %s", filename.string(), strerror(errno));
} else {
size_t length = size_t(stat.st_size);
FileMap* fileMap = new FileMap();
bool ownBuffer = false;
char* buffer;
if (fileMap->create(nullptr, fd, 0, length, true)) {
fileMap->advise(FileMap::SEQUENTIAL);
buffer = static_cast<char*>(fileMap->getDataPtr());
} else {
delete fileMap;
fileMap = nullptr;
// Fall back to reading into a buffer since we can't mmap files in sysfs.
// The length we obtained from stat is wrong too (it will always be 4096)
// so we must trust that read will read the entire file.
buffer = new char[length];
ownBuffer = true;
ssize_t nrd = read(fd, buffer, length);
if (nrd < 0) {
result = -errno;
ALOGE("Error reading file '%s': %s", filename.string(), strerror(errno));
delete[] buffer;
buffer = nullptr;
} else {
length = size_t(nrd);
}
}
if (!result) {
*outTokenizer = new Tokenizer(filename, fileMap, buffer, ownBuffer, length);
}
}
close(fd);
}
return result;
}
status_t Tokenizer::fromContents(const String8& filename,
const char* contents, Tokenizer** outTokenizer) {
*outTokenizer = new Tokenizer(filename, nullptr,
const_cast<char*>(contents), false, strlen(contents));
return OK;
}
String8 Tokenizer::getLocation() const {
String8 result;
result.appendFormat("%s:%d", mFilename.string(), mLineNumber);
return result;
}
String8 Tokenizer::peekRemainderOfLine() const {
const char* end = getEnd();
const char* eol = mCurrent;
while (eol != end) {
char ch = *eol;
if (ch == '\n') {
break;
}
eol += 1;
}
return String8(mCurrent, eol - mCurrent);
}
String8 Tokenizer::nextToken(const char* delimiters) {
#if DEBUG_TOKENIZER
ALOGD("nextToken");
#endif
const char* end = getEnd();
const char* tokenStart = mCurrent;
while (mCurrent != end) {
char ch = *mCurrent;
if (ch == '\n' || isDelimiter(ch, delimiters)) {
break;
}
mCurrent += 1;
}
return String8(tokenStart, mCurrent - tokenStart);
}
void Tokenizer::nextLine() {
#if DEBUG_TOKENIZER
ALOGD("nextLine");
#endif
const char* end = getEnd();
while (mCurrent != end) {
char ch = *(mCurrent++);
if (ch == '\n') {
mLineNumber += 1;
break;
}
}
}
void Tokenizer::skipDelimiters(const char* delimiters) {
#if DEBUG_TOKENIZER
ALOGD("skipDelimiters");
#endif
const char* end = getEnd();
while (mCurrent != end) {
char ch = *mCurrent;
if (ch == '\n' || !isDelimiter(ch, delimiters)) {
break;
}
mCurrent += 1;
}
}
} // namespace android