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/** |
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* This file is part of the CernVM File System. |
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* |
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* Some common functions. |
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*/ |
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#ifndef __STDC_FORMAT_MACROS |
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#define __STDC_FORMAT_MACROS |
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#endif |
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#include "cvmfs_config.h" |
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#include "mmap_file.h" |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <sys/mman.h> |
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#include <unistd.h> |
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#include <cassert> |
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#include "logging.h" |
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#include "platform.h" |
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using namespace std; // NOLINT |
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#ifdef CVMFS_NAMESPACE_GUARD |
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namespace CVMFS_NAMESPACE_GUARD { |
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#endif |
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MemoryMappedFile::MemoryMappedFile(const std::string &file_path) : |
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file_path_(file_path), |
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file_descriptor_(-1), |
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mapped_file_(NULL), |
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mapped_size_(0), |
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mapped_(false) {} |
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MemoryMappedFile::~MemoryMappedFile() { |
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✗✓ |
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if (IsMapped()) { |
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Unmap(); |
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} |
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} |
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bool MemoryMappedFile::Map() { |
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✗✓ |
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assert(!mapped_); |
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// open the file |
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int fd; |
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✗✓ |
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if ((fd = open(file_path_.c_str(), O_RDONLY, 0)) == -1) { |
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LogCvmfs(kLogUtility, kLogStderr, "failed to open %s (%d)", |
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file_path_.c_str(), errno); |
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return false; |
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} |
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// get file size |
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platform_stat64 filesize; |
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✗✓ |
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if (platform_fstat(fd, &filesize) != 0) { |
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LogCvmfs(kLogUtility, kLogStderr, "failed to fstat %s (%d)", |
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file_path_.c_str(), errno); |
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close(fd); |
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return false; |
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} |
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// check if the file is empty and 'pretend' that the file is mapped |
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// --> buffer will then look like a buffer without any size... |
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void *mapping = NULL; |
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✓✗ |
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if (filesize.st_size > 0) { |
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// map the given file into memory |
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mapping = mmap(NULL, filesize.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
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✗✓ |
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if (mapping == MAP_FAILED) { |
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LogCvmfs(kLogUtility, kLogStderr, "failed to mmap %s (file size: %d) " |
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"(errno: %d)", |
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file_path_.c_str(), |
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filesize.st_size, |
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errno); |
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close(fd); |
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return false; |
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} |
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} |
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// save results |
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mapped_file_ = static_cast<unsigned char*>(mapping); |
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file_descriptor_ = fd; |
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mapped_size_ = filesize.st_size; |
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mapped_ = true; |
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LogCvmfs(kLogUtility, kLogVerboseMsg, "mmap'ed %s", file_path_.c_str()); |
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return true; |
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} |
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void MemoryMappedFile::Unmap() { |
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✗✓ |
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assert(mapped_); |
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✗✓ |
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if (mapped_file_ == NULL) { |
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return; |
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} |
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// unmap the previously mapped file |
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✓✗✗✓
✗✓ |
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if ((munmap(static_cast<void*>(mapped_file_), mapped_size_) != 0) || |
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(close(file_descriptor_) != 0)) |
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{ |
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LogCvmfs(kLogUtility, kLogStderr, "failed to unmap %s", file_path_.c_str()); |
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const bool munmap_failed = false; |
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assert(munmap_failed); |
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} |
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// reset (resettable) data |
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mapped_file_ = NULL; |
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file_descriptor_ = -1; |
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mapped_size_ = 0; |
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mapped_ = false; |
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LogCvmfs(kLogUtility, kLogVerboseMsg, "munmap'ed %s", file_path_.c_str()); |
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} |
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#ifdef CVMFS_NAMESPACE_GUARD |
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} // namespace CVMFS_NAMESPACE_GUARD |
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#endif |