164 lines
3.5 KiB
C++
164 lines
3.5 KiB
C++
/* Generic stream implementation for OctaSTD.
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*
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* This file is part of OctaSTD. See COPYING.md for futher information.
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*/
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#ifndef OCTA_STREAM_H
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#define OCTA_STREAM_H
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#include <stdio.h>
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#include <sys/types.h>
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#include "octa/types.hh"
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#include "octa/range.hh"
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#include "octa/string.hh"
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#include "octa/type_traits.hh"
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namespace octa {
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/* off_t is POSIX - will also work on windows with mingw/clang, but FIXME */
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using StreamOffset = off_t;
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enum class StreamSeek {
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cur = SEEK_CUR,
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end = SEEK_END,
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set = SEEK_SET
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};
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template<typename T = char, bool = octa::IsPod<T>::value>
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struct StreamRange;
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struct Stream {
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using Offset = StreamOffset;
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virtual ~Stream() {}
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virtual void close() = 0;
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virtual bool end() const = 0;
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virtual Offset size() {
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Offset p = tell();
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if ((p < 0) || !seek(0, StreamSeek::end)) return -1;
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Offset e = tell();
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return ((p == e) || seek(p, StreamSeek::set)) ? e : -1;
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}
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virtual bool seek(Offset, StreamSeek = StreamSeek::set) {
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return false;
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}
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virtual Offset tell() const { return -1; }
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virtual bool flush() { return true; }
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virtual octa::Size read(void *, octa::Size) { return 0; }
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virtual octa::Size write(const void *, octa::Size) { return 0; }
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template<typename T = char>
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StreamRange<T> iter();
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};
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template<typename T>
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struct StreamRange<T, true>: InputRange<
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StreamRange<T>, octa::InputRangeTag, T, T, octa::Size, StreamOffset
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> {
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StreamRange(): p_stream(), p_size(0) {}
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StreamRange(Stream &s): p_stream(&s), p_size(s.size()) {}
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StreamRange(const StreamRange &r): p_stream(r.p_stream), p_size(r.p_size) {}
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bool empty() const {
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return p_stream->tell() == p_size;
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}
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bool pop_front() {
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if (empty()) return false;
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T val;
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return !!p_stream->read(&val, sizeof(T));
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}
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T front() const {
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T val;
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p_stream->seek(-p_stream->read(&val, sizeof(T)), StreamSeek::cur);
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return val;
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}
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virtual bool equals_front(const StreamRange &s) const {
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return p_stream->tell() == s.p_stream->tell();
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}
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void put(T val) {
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p_size += p_stream->write(&val, sizeof(T));
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}
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private:
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Stream *p_stream;
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StreamOffset p_size;
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};
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template<typename T>
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inline StreamRange<T> Stream::iter() {
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return StreamRange<T>(*this);
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}
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enum class StreamMode {
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read, write, append,
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update = 1 << 2
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};
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namespace detail {
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static const char *filemodes[] = {
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"rb", "wb", "ab", nullptr, "rb+", "wb+", "ab+"
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};
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}
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struct FileStream: Stream {
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FileStream(): p_f() {}
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FileStream(const FileStream &s) = delete;
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FileStream(const octa::String &path, StreamMode mode): p_f() {
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open(path, mode);
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}
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~FileStream() { close(); }
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bool open(const octa::String &path, StreamMode mode) {
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if (p_f) return false;
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p_f = fopen(path.data(), octa::detail::filemodes[octa::Size(mode)]);
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return p_f != nullptr;
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}
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void close() {
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if (p_f) fclose(p_f);
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p_f = nullptr;
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}
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bool end() const {
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return feof(p_f) != 0;
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}
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bool seek(StreamOffset pos, StreamSeek whence = StreamSeek::set) {
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return fseeko(p_f, pos, int(whence)) >= 0;
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}
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StreamOffset tell() const {
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return ftello(p_f);
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}
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bool flush() { return !fflush(p_f); }
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octa::Size read(void *buf, octa::Size count) {
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return fread(buf, 1, count, p_f);
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}
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octa::Size write(const void *buf, octa::Size count) {
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return fwrite(buf, 1, count, p_f);
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}
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private:
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FILE *p_f;
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};
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}
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#endif |