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A fork of https://github.com/crosspoint-reader/crosspoint-reader
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2.3 kB · 78 lines
C++
at master
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879#include "InflateReader.h"
#include <cstring>#include <type_traits>
namespace {constexpr size_t INFLATE_DICT_SIZE = 32768;}
// Guarantee the cast pattern in the header comment is valid.static_assert(std::is_standard_layout<InflateReader>::value, "InflateReader must be standard-layout for the uzlib callback cast to work");
InflateReader::~InflateReader() { deinit(); }
bool InflateReader::init(const bool streaming) { deinit(); // free any previously allocated ring buffer and reset state
if (streaming) { ringBuffer = static_cast<uint8_t*>(malloc(INFLATE_DICT_SIZE)); if (!ringBuffer) return false; memset(ringBuffer, 0, INFLATE_DICT_SIZE); }
uzlib_uncompress_init(&decomp, ringBuffer, ringBuffer ? INFLATE_DICT_SIZE : 0); return true;}
void InflateReader::deinit() { if (ringBuffer) { free(ringBuffer); ringBuffer = nullptr; } memset(&decomp, 0, sizeof(decomp));}
void InflateReader::setSource(const uint8_t* src, size_t len) { decomp.source = src; decomp.source_limit = src + len;}
void InflateReader::setReadCallback(int (*cb)(struct uzlib_uncomp*)) { decomp.source_read_cb = cb; }
void InflateReader::skipZlibHeader() { uzlib_get_byte(&decomp); uzlib_get_byte(&decomp);}
bool InflateReader::read(uint8_t* dest, size_t len) { if (!ringBuffer) { // One-shot mode: back-references use absolute offset from dest_start. // Valid only when read() is called once with the full output buffer. decomp.dest_start = dest; } decomp.dest = dest; decomp.dest_limit = dest + len;
const int res = uzlib_uncompress(&decomp); if (res < 0) return false; return decomp.dest == decomp.dest_limit;}
InflateStatus InflateReader::readAtMost(uint8_t* dest, size_t maxLen, size_t* produced) { if (!ringBuffer) { // One-shot mode: back-references use absolute offset from dest_start. // Valid only when readAtMost() is called once with the full output buffer. decomp.dest_start = dest; } decomp.dest = dest; decomp.dest_limit = dest + maxLen;
const int res = uzlib_uncompress(&decomp); *produced = static_cast<size_t>(decomp.dest - dest);
if (res == TINF_DONE) return InflateStatus::Done; if (res < 0) return InflateStatus::Error; return InflateStatus::Ok;}