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simdjson-simdjson/include/simdjson/haswell/stringparsing.h
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2021-06-19 21:20:31 -07:00

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#ifndef SIMDJSON_HASWELL_STRINGPARSING_H
#define SIMDJSON_HASWELL_STRINGPARSING_H
#include "simdjson/base.h"
#include "simdjson/haswell/simd.h"
#include "simdjson/haswell/bitmanipulation.h"
namespace simdjson {
namespace SIMDJSON_IMPLEMENTATION {
namespace {
using namespace simd;
// Holds backslashes and quotes locations.
struct backslash_and_quote {
public:
static constexpr uint32_t BYTES_PROCESSED = 32;
simdjson_really_inline static backslash_and_quote
copy_and_find(const uint8_t *src, uint8_t *dst, const uint8_t *last_full_buf);
simdjson_really_inline static backslash_and_quote
copy_and_find(const uint8_t *src, uint8_t *dst);
simdjson_really_inline bool has_quote_first() { return ((bs_bits - 1) & quote_bits) != 0; }
simdjson_really_inline bool has_backslash() { return ((quote_bits - 1) & bs_bits) != 0; }
simdjson_really_inline int quote_index() { return trailing_zeroes(quote_bits); }
simdjson_really_inline int backslash_index() { return trailing_zeroes(bs_bits); }
uint32_t bs_bits;
uint32_t quote_bits;
}; // struct backslash_and_quote
simdjson_really_inline backslash_and_quote
backslash_and_quote::copy_and_find(const uint8_t *src, uint8_t *dst, const uint8_t *last_full_buf) {
// If we don't have enough memory left to load a whole simd register, copy it first.
uint8_t tmpbuf[BYTES_PROCESSED];
if (simdjson_unlikely(src > last_full_buf)) {
SIMDJSON_ASSUME(last_full_buf+BYTES_PROCESSED > src);
std::memset(tmpbuf, 0, BYTES_PROCESSED);
std::memcpy(tmpbuf, src, last_full_buf+BYTES_PROCESSED-src);
src = tmpbuf;
}
return copy_and_find(src, dst);
}
simdjson_really_inline backslash_and_quote
backslash_and_quote::copy_and_find(const uint8_t *src, uint8_t *dst) {
// this can read up to 15 bytes beyond the buffer size, but we require
// SIMDJSON_PADDING of padding
static_assert(SIMDJSON_PADDING >= (BYTES_PROCESSED - 1), "backslash and quote finder must process fewer than SIMDJSON_PADDING bytes");
simd8<uint8_t> v(src);
// store to dest unconditionally - we can overwrite the bits we don't like later
v.store(dst);
return {
static_cast<uint32_t>((v == '\\').to_bitmask()), // bs_bits
static_cast<uint32_t>((v == '"').to_bitmask()), // quote_bits
};
}
} // unnamed namespace
} // namespace SIMDJSON_IMPLEMENTATION
} // namespace simdjson
#include "simdjson/generic/stringparsing.h"
#endif // SIMDJSON_HASWELL_STRINGPARSING_H