63 lines
1.6 KiB
C++
63 lines
1.6 KiB
C++
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#include "MmapFile.hpp"
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#include <fcntl.h>
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#include <sys/file.h>
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#include <sys/mman.h>
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namespace lightningbolt {
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struct MmapFile::Impl {
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~Impl() {
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Close();
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}
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void Close() {
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if(mapping) {
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munmap(mapping, mappingSize);
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mapping = nullptr;
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mappingSize = 0;
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}
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}
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ErrorOr<void> Open(const fs::path& path) {
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int fd = open(path.string().c_str(), O_RDONLY);
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// Error opening file.
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if(fd == -1)
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return std::error_code{errno, std::system_category()};
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{
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auto last = lseek64(fd, 0, SEEK_END);
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mappingSize = lseek64(fd, 0, SEEK_CUR);
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lseek64(fd, last, SEEK_SET);
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}
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mapping = static_cast<u8*>(mmap(nullptr, mappingSize, PROT_READ, MAP_PRIVATE, fd, 0));
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if(mapping == static_cast<u8*>(MAP_FAILED)) {
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mappingSize = 0;
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return std::error_code{errno, std::system_category()};
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}
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// Once the mapping has successfully been created
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// we can close the file descriptor instead of needing
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// to remember it (the kernel will do so for us.)
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close(fd);
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// No error.
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return {};
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}
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u8* GetMapping() const {
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return mapping;
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}
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usize GetMappingSize() const {
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return mappingSize;
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}
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private:
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u8* mapping;
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usize mappingSize;
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};
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} // namespace lightningbolt
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