michael@0: /*
michael@0:  * Copyright (C) 2010 The Android Open Source Project
michael@0:  *
michael@0:  * Licensed under the Apache License, Version 2.0 (the "License");
michael@0:  * you may not use this file except in compliance with the License.
michael@0:  * You may obtain a copy of the License at
michael@0:  *
michael@0:  *      http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing, software
michael@0:  * distributed under the License is distributed on an "AS IS" BASIS,
michael@0:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0:  * See the License for the specific language governing permissions and
michael@0:  * limitations under the License.
michael@0:  */
michael@0: 
michael@0: #define LOG_TAG "Tokenizer"
michael@0: #include "cutils_log.h"
michael@0: 
michael@0: #include <stdlib.h>
michael@0: #include <unistd.h>
michael@0: #include <fcntl.h>
michael@0: #include <errno.h>
michael@0: #include <sys/types.h>
michael@0: #include <sys/stat.h>
michael@0: #include "Tokenizer.h"
michael@0: 
michael@0: // Enables debug output for the tokenizer.
michael@0: #define DEBUG_TOKENIZER 0
michael@0: 
michael@0: 
michael@0: namespace android {
michael@0: 
michael@0: static inline bool isDelimiter(char ch, const char* delimiters) {
michael@0:     return strchr(delimiters, ch) != NULL;
michael@0: }
michael@0: 
michael@0: Tokenizer::Tokenizer(const String8& filename, FileMap* fileMap, char* buffer,
michael@0:         bool ownBuffer, size_t length) :
michael@0:         mFilename(filename), mFileMap(fileMap),
michael@0:         mBuffer(buffer), mOwnBuffer(ownBuffer), mLength(length),
michael@0:         mCurrent(buffer), mLineNumber(1) {
michael@0: }
michael@0: 
michael@0: Tokenizer::~Tokenizer() {
michael@0:     if (mFileMap) {
michael@0:         mFileMap->release();
michael@0:     }
michael@0:     if (mOwnBuffer) {
michael@0:         delete[] mBuffer;
michael@0:     }
michael@0: }
michael@0: 
michael@0: status_t Tokenizer::open(const String8& filename, Tokenizer** outTokenizer) {
michael@0:     *outTokenizer = NULL;
michael@0: 
michael@0:     int result = NO_ERROR;
michael@0:     int fd = ::open(filename.string(), O_RDONLY);
michael@0:     if (fd < 0) {
michael@0:         result = -errno;
michael@0:         ALOGE("Error opening file '%s', %s.", filename.string(), strerror(errno));
michael@0:     } else {
michael@0:         struct stat stat;
michael@0:         if (fstat(fd, &stat)) {
michael@0:             result = -errno;
michael@0:             ALOGE("Error getting size of file '%s', %s.", filename.string(), strerror(errno));
michael@0:         } else {
michael@0:             size_t length = size_t(stat.st_size);
michael@0: 
michael@0:             FileMap* fileMap = new FileMap();
michael@0:             bool ownBuffer = false;
michael@0:             char* buffer;
michael@0:             if (fileMap->create(NULL, fd, 0, length, true)) {
michael@0:                 fileMap->advise(FileMap::SEQUENTIAL);
michael@0:                 buffer = static_cast<char*>(fileMap->getDataPtr());
michael@0:             } else {
michael@0:                 fileMap->release();
michael@0:                 fileMap = NULL;
michael@0: 
michael@0:                 // Fall back to reading into a buffer since we can't mmap files in sysfs.
michael@0:                 // The length we obtained from stat is wrong too (it will always be 4096)
michael@0:                 // so we must trust that read will read the entire file.
michael@0:                 buffer = new char[length];
michael@0:                 ownBuffer = true;
michael@0:                 ssize_t nrd = read(fd, buffer, length);
michael@0:                 if (nrd < 0) {
michael@0:                     result = -errno;
michael@0:                     ALOGE("Error reading file '%s', %s.", filename.string(), strerror(errno));
michael@0:                     delete[] buffer;
michael@0:                     buffer = NULL;
michael@0:                 } else {
michael@0:                     length = size_t(nrd);
michael@0:                 }
michael@0:             }
michael@0: 
michael@0:             if (!result) {
michael@0:                 *outTokenizer = new Tokenizer(filename, fileMap, buffer, ownBuffer, length);
michael@0:             }
michael@0:         }
michael@0:         close(fd);
michael@0:     }
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: status_t Tokenizer::fromContents(const String8& filename,
michael@0:         const char* contents, Tokenizer** outTokenizer) {
michael@0:     *outTokenizer = new Tokenizer(filename, NULL,
michael@0:             const_cast<char*>(contents), false, strlen(contents));
michael@0:     return OK;
michael@0: }
michael@0: 
michael@0: String8 Tokenizer::getLocation() const {
michael@0:     String8 result;
michael@0:     result.appendFormat("%s:%d", mFilename.string(), mLineNumber);
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: String8 Tokenizer::peekRemainderOfLine() const {
michael@0:     const char* end = getEnd();
michael@0:     const char* eol = mCurrent;
michael@0:     while (eol != end) {
michael@0:         char ch = *eol;
michael@0:         if (ch == '\n') {
michael@0:             break;
michael@0:         }
michael@0:         eol += 1;
michael@0:     }
michael@0:     return String8(mCurrent, eol - mCurrent);
michael@0: }
michael@0: 
michael@0: String8 Tokenizer::nextToken(const char* delimiters) {
michael@0: #if DEBUG_TOKENIZER
michael@0:     ALOGD("nextToken");
michael@0: #endif
michael@0:     const char* end = getEnd();
michael@0:     const char* tokenStart = mCurrent;
michael@0:     while (mCurrent != end) {
michael@0:         char ch = *mCurrent;
michael@0:         if (ch == '\n' || isDelimiter(ch, delimiters)) {
michael@0:             break;
michael@0:         }
michael@0:         mCurrent += 1;
michael@0:     }
michael@0:     return String8(tokenStart, mCurrent - tokenStart);
michael@0: }
michael@0: 
michael@0: void Tokenizer::nextLine() {
michael@0: #if DEBUG_TOKENIZER
michael@0:     ALOGD("nextLine");
michael@0: #endif
michael@0:     const char* end = getEnd();
michael@0:     while (mCurrent != end) {
michael@0:         char ch = *(mCurrent++);
michael@0:         if (ch == '\n') {
michael@0:             mLineNumber += 1;
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: void Tokenizer::skipDelimiters(const char* delimiters) {
michael@0: #if DEBUG_TOKENIZER
michael@0:     ALOGD("skipDelimiters");
michael@0: #endif
michael@0:     const char* end = getEnd();
michael@0:     while (mCurrent != end) {
michael@0:         char ch = *mCurrent;
michael@0:         if (ch == '\n' || !isDelimiter(ch, delimiters)) {
michael@0:             break;
michael@0:         }
michael@0:         mCurrent += 1;
michael@0:     }
michael@0: }
michael@0: 
michael@0: } // namespace android