forked from OctaForge/libostd
216 lines
4.9 KiB
C++
216 lines
4.9 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 OSTD_STREAM_HH
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#define OSTD_STREAM_HH
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#include <sys/types.h>
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#include <type_traits>
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#include "ostd/platform.hh"
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#include "ostd/types.hh"
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#include "ostd/range.hh"
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#include "ostd/string.hh"
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#include "ostd/utility.hh"
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#include "ostd/format.hh"
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namespace ostd {
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#ifndef OSTD_PLATFORM_WIN32
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using StreamOffset = off_t;
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#else
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using StreamOffset = __int64;
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#endif
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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 = std::is_pod_v<T>>
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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)) {
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return -1;
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}
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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 size_t read_bytes(void *, size_t) { return 0; }
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virtual size_t write_bytes(void const *, size_t) { return 0; }
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virtual int getchar() {
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byte c;
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return (read_bytes(&c, 1) == 1) ? c : -1;
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}
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virtual bool putchar(int c) {
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byte wc = byte(c);
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return write_bytes(&wc, 1) == 1;
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}
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template<typename T>
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bool write(T const &v);
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template<typename T, typename ...A>
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bool write(T const &v, A const &...args) {
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return write(v) && write(args...);
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}
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template<typename T>
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bool writeln(T const &v) {
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return write(v) && putchar('\n');
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}
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template<typename T, typename ...A>
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bool writeln(T const &v, A const &...args) {
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return write(v) && write(args...) && putchar('\n');
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}
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template<typename ...A>
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bool writef(ConstCharRange fmt, A const &...args);
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template<typename ...A>
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bool writefln(ConstCharRange fmt, A const &...args) {
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return writef(fmt, args...) && putchar('\n');
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}
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template<typename T = char>
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StreamRange<T> iter();
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template<typename T>
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size_t put(T const *v, size_t count) {
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return write_bytes(v, count * sizeof(T)) / sizeof(T);
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}
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template<typename T>
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bool put(T v) {
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return write_bytes(&v, sizeof(T)) == sizeof(T);
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}
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template<typename T>
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size_t get(T *v, size_t count) {
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return read_bytes(v, count * sizeof(T)) / sizeof(T);
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}
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template<typename T>
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bool get(T &v) {
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return read_bytes(&v, sizeof(T)) == sizeof(T);
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}
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template<typename T>
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T get() {
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T r;
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return get(r) ? r : T();
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}
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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>, InputRangeTag, T, T, size_t, StreamOffset
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> {
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StreamRange() = delete;
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StreamRange(Stream &s): p_stream(&s), p_size(s.size()) {}
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StreamRange(StreamRange const &r): p_stream(r.p_stream), p_size(r.p_size) {}
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bool empty() const {
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return (p_size - p_stream->tell()) < StreamOffset(sizeof(T));
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}
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bool pop_front() {
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if (empty()) {
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return false;
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}
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T val;
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return !!p_stream->read_bytes(&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_bytes(&val, sizeof(T)), StreamSeek::cur);
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return val;
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}
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bool equals_front(StreamRange const &s) const {
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return p_stream->tell() == s.p_stream->tell();
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}
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bool put(T val) {
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size_t v = p_stream->write_bytes(&val, sizeof(T));
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p_size += v;
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return (v == sizeof(T));
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}
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size_t put_n(T const *p, size_t n) {
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return p_stream->put(p, n);
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}
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size_t copy(std::remove_cv_t<T> *p, size_t n = -1) {
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if (n == size_t(-1)) {
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n = p_stream->size() / sizeof(T);
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}
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return p_stream->get(p, n);
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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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namespace detail {
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/* lightweight output range for write/writef on streams */
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struct FmtStreamRange: OutputRange<FmtStreamRange, char> {
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FmtStreamRange(Stream &s): p_s(s) {}
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bool put(char c) {
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return p_s.write_bytes(&c, 1) == 1;
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}
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size_t put_n(char const *p, size_t n) {
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return p_s.write_bytes(p, n);
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}
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Stream &p_s;
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};
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}
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template<typename T>
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inline bool Stream::write(T const &v) {
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// TODO: switch to direct FormatSpec later
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return format(detail::FmtStreamRange{*this}, "%s", v) >= 0;
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}
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template<typename ...A>
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inline bool Stream::writef(ConstCharRange fmt, A const &...args) {
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return format(detail::FmtStreamRange{*this}, fmt, args...) >= 0;
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}
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}
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#endif
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