public static bool json_parse(uint8_t *buf, size_t len, ParsedJson *pj, bool reallocifneeded = true)
{
if (pj->bytecapacity < len)
{
Debug.WriteLine("Your ParsedJson cannot support documents that big: " + len);
return(false);
}
bool reallocated = false;
if (reallocifneeded)
{
// realloc is needed if the end of the memory crosses a page
long pagesize = System.Environment.SystemPageSize;
if (((size_t)(buf + len - 1) % (size_t)pagesize) < SIMDJSON_PADDING)
{
uint8_t *tmpbuf = buf;
buf = (uint8_t *)Utils.allocate_padded_buffer(len);
if (buf == null)
{
return(false);
}
memcpy((void *)buf, tmpbuf, len);
reallocated = true;
}
}
bool isok = stage1_find_marks.find_structural_bits(buf, len, pj);
if (isok)
{
isok = stage2_build_tape.unified_machine(buf, len, pj);
}
else
{
if (reallocated)
{
Utils.free((void *)buf);
}
return(false);
}
if (reallocated)
{
Utils.free((void *)buf);
}
return(isok);
}
public iterator(ParsedJson *pj)
{
this.pj = pj;
depth = 0;
location = 0;
tape_length = 0;
depthindex = null;
current_type = 0;
current_val = 0;
if (pj->isValid())
{
depthindex = allocate <scopeindex_t>(pj->depthcapacity);
if (depthindex == null)
{
return;
}
depthindex[0].start_of_scope = location;
current_val = pj->tape[location++];
current_type = (uint8_t)(current_val >> 56);
depthindex[0].scope_type = current_type;
if (current_type == 'r')
{
tape_length = current_val & JSONVALUEMASK;
if (location < tape_length)
{
current_val = pj->tape[location];
current_type = (uint8_t)(current_val >> 56);
depth++;
depthindex[depth].start_of_scope = location;
depthindex[depth].scope_type = current_type;
}
}
}
else
{
throw new InvalidOperationException("Json is invalid");
}
}
public static bool parse_string(uint8_t *buf, size_t len, ParsedJson *pj, uint32_t depth, uint32_t offset)
{
#if SIMDJSON_SKIPSTRINGPARSING // for performance analysis, it is sometimes useful to skip parsing
pj->write_tape(0, '"'); // don't bother with the string parsing at all
return(true); // always succeeds
#else
uint8_t *src = &buf[offset + 1]; // we know that buf at offset is a "
uint8_t *dst = pj->current_string_buf_loc;
#if JSON_TEST_STRINGS // for unit testing
uint8_t *const start_of_string = dst;
#endif
var slashVec = Vector256.Create((byte)'\\');
var quoteVec = Vector256.Create((byte)'"');
while (true)
{
Vector256 <byte> v = Avx2.LoadVector256((src));
uint32_t bs_bits =
(uint32_t)Avx2.MoveMask(Avx2.CompareEqual(v, slashVec));
uint32_t quote_bits =
(uint32_t)Avx2.MoveMask(Avx2.CompareEqual(v, quoteVec));
// All Unicode characters may be placed within the
// quotation marks, except for the characters that MUST be escaped:
// quotation mark, reverse solidus, and the control characters (U+0000
//through U+001F).
// https://tools.ietf.org/html/rfc8259
#if CHECKUNESCAPED
var unitsep = Vector256.Create((byte)0x1F);
var unescaped_vec =
Avx2.CompareEqual(Avx2.Max(unitsep, v), unitsep); // could do it with saturated subtraction
#endif // CHECKUNESCAPED
uint32_t quote_dist = (uint32_t)trailingzeroes(quote_bits);
uint32_t bs_dist = (uint32_t)trailingzeroes(bs_bits);
// store to dest unconditionally - we can overwrite the bits we don't like
// later
Avx.Store((dst), v);
if (quote_dist < bs_dist)
{
// we encountered quotes first. Move dst to point to quotes and exit
dst[quote_dist] = 0; // null terminate and get out
pj->write_tape((size_t)pj->current_string_buf_loc - (size_t)pj->string_buf, (uint8_t)'"');
pj->current_string_buf_loc = dst + quote_dist + 1; // the +1 is due to the 0 value
#if CHECKUNESCAPED
// check that there is no unescaped char before the quote
uint32_t unescaped_bits = (uint32_t)Avx2.MoveMask(unescaped_vec);
bool is_ok = ((quote_bits - 1) & (~quote_bits) & unescaped_bits) == 0;
#if JSON_TEST_STRINGS // for unit testing
if (is_ok)
{
foundString(buf + offset, start_of_string, pj->current_string_buf_loc - 1);
}
else
{
foundBadString(buf + offset);
}
#endif // JSON_TEST_STRINGS
return(is_ok);
#else //CHECKUNESCAPED
#if JSON_TEST_STRINGS // for unit testing
foundString(buf + offset, start_of_string, pj->current_string_buf_loc - 1);
#endif // JSON_TEST_STRINGS
return(true);
#endif //CHECKUNESCAPED
}
else if (quote_dist > bs_dist)
{
uint8_t escape_char = src[bs_dist + 1];
#if CHECKUNESCAPED
// we are going to need the unescaped_bits to check for unescaped chars
uint32_t unescaped_bits = (uint32_t)Avx2.MoveMask(unescaped_vec);
if (((bs_bits - 1) & (~bs_bits) & unescaped_bits) != 0)
{
#if JSON_TEST_STRINGS // for unit testing
foundBadString(buf + offset);
#endif // JSON_TEST_STRINGS
return(false);
}
#endif //CHECKUNESCAPED
// we encountered backslash first. Handle backslash
if (escape_char == 'u')
{
// move src/dst up to the start; they will be further adjusted
// within the unicode codepoint handling code.
src += bs_dist;
dst += bs_dist;
if (!handle_unicode_codepoint(&src, &dst))
{
#if JSON_TEST_STRINGS // for unit testing
foundBadString(buf + offset);
#endif // JSON_TEST_STRINGS
return(false);
}
}
else
{
// simple 1:1 conversion. Will eat bs_dist+2 characters in input and
// write bs_dist+1 characters to output
// note this may reach beyond the part of the buffer we've actually
// seen. I think this is ok
uint8_t escape_result = escape_map[escape_char];
if (escape_result == 0)
{
#if JSON_TEST_STRINGS // for unit testing
foundBadString(buf + offset);
#endif // JSON_TEST_STRINGS
return(false); // bogus escape value is an error
}
dst[bs_dist] = escape_result;
src += bs_dist + 2;
dst += bs_dist + 1;
}
}
else
{
// they are the same. Since they can't co-occur, it means we encountered
// neither.
src += 32;
dst += 32;
#if CHECKUNESCAPED
// check for unescaped chars
if (Avx.TestZ(unescaped_vec, unescaped_vec) != true)
{
#if JSON_TEST_STRINGS // for unit testing
foundBadString(buf + offset);
#endif // JSON_TEST_STRINGS
return(false);
}
#endif // CHECKUNESCAPED
}
}
// can't be reached
return(true);
#endif // SIMDJSON_SKIPSTRINGPARSING
}
public static bool parse_number(uint8_t *buf, ParsedJson *pj, uint32_t offset, bool found_minus)
{
bytechar *p = (bytechar *)(buf + offset);
bool negative = false;
if (found_minus)
{
++p;
negative = true;
if (!is_integer(*p))
{
// a negative sign must be followed by an integer
return(false);
}
}
bytechar *startdigits = p;
int64_t i;
if (*p == '0')
{
// 0 cannot be followed by an integer
++p;
if (is_not_structural_or_whitespace_or_exponent_or_decimal((uint8_t)(*p)))
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
i = 0;
}
else
{
if (!(is_integer(*p)))
{
// must start with an integer
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
i = digit;
p++;
// the is_made_of_eight_digits_fast routine is unlikely to help here because
// we rarely see large integer parts like 123456789
while (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
i = 10 * i + digit; // might overflow
++p;
}
}
int64_t exponent = 0;
if ('.' == *p)
{
++p;
bytechar *firstafterperiod = p;
if (is_integer(*p))
{
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
++p;
i = i * 10 + digit;
}
else
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
#if SWAR_NUMBER_PARSING
// this helps if we have lots of decimals!
// this turns out to be frequent enough.
if (is_made_of_eight_digits_fast(p))
{
i = i * 100000000 + parse_eight_digits_unrolled(p);
p += 8;
// exponent -= 8;
}
#endif
while (is_integer(*p))
{
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
++p;
i = i * 10 + digit; // in rare cases, this will overflow, but that's ok because we have parse_highprecision_float later.
}
exponent = firstafterperiod - p;
}
int digitcount = (int)(p - startdigits - 1);
int64_t expnumber = 0; // exponential part
if (('e' == *p) || ('E' == *p))
{
++p;
bool negexp = false;
if ('-' == *p)
{
negexp = true;
++p;
}
else if ('+' == *p)
{
++p;
}
if (!is_integer(*p))
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
expnumber = digit;
p++;
while (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
expnumber = 10 * expnumber + digit;
++p;
}
if (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
expnumber = 10 * expnumber + digit;
++p;
}
if (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
expnumber = 10 * expnumber + digit;
++p;
}
if (is_integer(*p))
{
// we refuse to parse this
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
exponent += (negexp ? -expnumber : expnumber);
}
i = negative ? -i : i;
if ((exponent != 0) || (expnumber != 0))
{
if ((digitcount >= 19))
{
// this is uncommon!!!
// this is almost never going to get called!!!
// we start anew, going slowly!!!
return(parse_float(buf, pj, offset,
found_minus));
}
///////////
// We want 0.1e1 to be a float.
//////////
if (i == 0)
{
pj->write_tape_double(0.0);
#if JSON_TEST_NUMBERS // for unit testing
foundFloat(0.0, buf + offset);
#endif
}
else
{
if ((exponent > 308) || (exponent < -308))
{
// we refuse to parse this
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
double d = i;
d *= power_of_ten[308 + exponent];
// d = negative ? -d : d;
pj->write_tape_double(d);
#if JSON_TEST_NUMBERS // for unit testing
foundFloat(d, buf + offset);
#endif
}
}
else
{
if ((digitcount >= 18))
{
// this is uncommon!!!
return(parse_large_integer(buf, pj, offset,
found_minus));
}
pj->write_tape_s64(i);
#if JSON_TEST_NUMBERS // for unit testing
foundInteger(i, buf + offset);
#endif
}
return(is_structural_or_whitespace((uint8_t)(*p)) != 0);
}
// called by parse_number when we know that the output is an integer,
// but where there might be some integer overflow.
// we want to catch overflows!
// Do not call this function directly as it skips some of the checks from
// parse_number
//
// This function will almost never be called!!!
//
static bool parse_large_integer(uint8_t *buf, ParsedJson *pj, uint32_t offset, bool found_minus)
{
bytechar *p = (bytechar *)(buf + offset);
bool negative = false;
if (found_minus)
{
++p;
negative = true;
}
uint64_t i;
if (*p == '0')
{
// 0 cannot be followed by an integer
++p;
i = 0;
}
else
{
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
i = digit;
p++;
// the is_made_of_eight_digits_fast routine is unlikely to help here because
// we rarely see large integer parts like 123456789
while (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
if (mul_overflow(i, 10, &i))
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false); // overflow
}
if (add_overflow(i, digit, &i))
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false); // overflow
}
++p;
}
}
if (negative)
{
if (i > 0x8000000000000000)
{
// overflows!
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false); // overflow
}
}
else
{
if (i >= 0x8000000000000000)
{
// overflows!
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false); // overflow
}
}
int64_t signed_answer = negative ? -(int64_t)i : (int64_t)i;
pj->write_tape_s64(signed_answer);
#if JSON_TEST_NUMBERS // for unit testing
foundInteger(signed_answer, buf + offset);
#endif
return(is_structural_or_whitespace((byte)(*p)) != 0);
}
// called by parse_number when we know that the output is a float,
// but where there might be some integer overflow. The trick here is to
// parse using floats from the start.
// Do not call this function directly as it skips some of the checks from
// parse_number
//
// This function will almost never be called!!!
//
// Note: a redesign could avoid this function entirely.
//
private static bool parse_float(uint8_t *buf, ParsedJson *pj, uint32_t offset, bool found_minus)
{
bytechar *p = (bytechar *)(buf + offset);
bool negative = false;
if (found_minus)
{
++p;
negative = true;
}
double i;
if (*p == '0')
{
// 0 cannot be followed by an integer
++p;
i = 0;
}
else
{
unsigned_bytechar digit = (unsigned_bytechar)(*p - (bytechar)'0');
i = digit;
p++;
while (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
i = 10 * i + digit;
++p;
}
}
if ('.' == *p)
{
++p;
double fractionalweight = 1;
if (is_integer(*p))
{
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
++p;
fractionalweight *= 0.1;
i = i + digit * fractionalweight;
}
else
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
while (is_integer(*p))
{
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
++p;
fractionalweight *= 0.1;
i = i + digit * fractionalweight;
}
}
if (('e' == *p) || ('E' == *p))
{
++p;
bool negexp = false;
if ('-' == *p)
{
negexp = true;
++p;
}
else if ('+' == *p)
{
++p;
}
if (!is_integer(*p))
{
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
unsigned_bytechar digit = (unsigned_bytechar)(*p - '0');
int64_t expnumber = digit; // exponential part
p++;
if (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
expnumber = 10 * expnumber + digit;
++p;
}
if (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
expnumber = 10 * expnumber + digit;
++p;
}
if (is_integer(*p))
{
digit = (unsigned_bytechar)(*p - '0');
expnumber = 10 * expnumber + digit;
++p;
}
if (is_integer(*p))
{
// we refuse to parse this
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
int exponent = (int)(negexp ? -expnumber : expnumber);
if ((exponent > 308) || (exponent < -308))
{
// we refuse to parse this
#if JSON_TEST_NUMBERS // for unit testing
foundInvalidNumber(buf + offset);
#endif
return(false);
}
i *= power_of_ten[308 + exponent];
}
if (is_not_structural_or_whitespace((byte)*p) != 0)
{
return(false);
}
double d = negative ? -i : i;
pj->write_tape_double(d);
#if JSON_TEST_NUMBERS // for unit testing
foundFloat(d, buf + offset);
#endif
return(is_structural_or_whitespace((byte)(*p)) != 0);
}
public static bool find_structural_bits(uint8_t *buf, size_t len, ParsedJson *pj)
{
if (len > pj->bytecapacity)
{
Console.WriteLine("Your ParsedJson object only supports documents up to " + pj->bytecapacity +
" bytes but you are trying to process " + len + " bytes\n");
return(false);
}
uint32_t *base_ptr = pj->structural_indexes;
uint32_t @base = 0;
const uint64_t even_bits = 0x5555555555555555UL;
const uint64_t odd_bits = ~even_bits;
// for now, just work in 64-byte chunks
// we have padded the input out to 64 byte multiple with the remainder being
// zeros
// persistent state across loop
uint64_t prev_iter_ends_odd_backslash = 0UL; // either 0 or 1, but a 64-bit value
uint64_t prev_iter_inside_quote = 0UL; // either all zeros or all ones
// effectively the very first char is considered to follow "whitespace" for the
// purposes of psuedo-structural character detection
uint64_t prev_iter_ends_pseudo_pred = 1UL;
size_t lenminus64 = len < 64 ? 0 : len - 64;
size_t idx = 0;
uint64_t structurals = 0;
// C#: assign static readonly fields to locals before the loop
Vector256 <byte> low_nibble_mask = s_low_nibble_mask;
Vector256 <byte> high_nibble_mask = s_high_nibble_mask;
var structural_shufti_mask = Vector256.Create((byte)0x7);
var whitespace_shufti_mask = Vector256.Create((byte)0x18);
var slashVec = Vector256.Create((bytechar)'\\').AsByte();
var ffVec = Vector128.Create((byte)0xFF).AsUInt64();
var doubleQuoteVec = Vector256.Create((byte)'"');
var zeroBVec = Vector256.Create((byte)0);
var vec7f = Vector256.Create((byte)0x7f);
for (; idx < lenminus64; idx += 64)
{
var input_lo = Avx.LoadVector256(buf + idx + 0);
var input_hi = Avx.LoadVector256(buf + idx + 32);
////////////////////////////////////////////////////////////////////////////////////////////
// Step 1: detect odd sequences of backslashes
////////////////////////////////////////////////////////////////////////////////////////////
///
uint64_t bs_bits =
cmp_mask_against_input(input_lo, input_hi, slashVec);
uint64_t start_edges = bs_bits & ~(bs_bits << 1);
// flip lowest if we have an odd-length run at the end of the prior
// iteration
uint64_t even_start_mask = even_bits ^ prev_iter_ends_odd_backslash;
uint64_t even_starts = start_edges & even_start_mask;
uint64_t odd_starts = start_edges & ~even_start_mask;
uint64_t even_carries = bs_bits + even_starts;
uint64_t odd_carries;
// must record the carry-out of our odd-carries out of bit 63; this
// indicates whether the sense of any edge going to the next iteration
// should be flipped
bool iter_ends_odd_backslash =
add_overflow(bs_bits, odd_starts, &odd_carries);
odd_carries |=
prev_iter_ends_odd_backslash; // push in bit zero as a potential end
// if we had an odd-numbered run at the
// end of the previous iteration
prev_iter_ends_odd_backslash = iter_ends_odd_backslash ? 0x1UL : 0x0UL;
uint64_t even_carry_ends = even_carries & ~bs_bits;
uint64_t odd_carry_ends = odd_carries & ~bs_bits;
uint64_t even_start_odd_end = even_carry_ends & odd_bits;
uint64_t odd_start_even_end = odd_carry_ends & even_bits;
uint64_t odd_ends = even_start_odd_end | odd_start_even_end;
////////////////////////////////////////////////////////////////////////////////////////////
// Step 2: detect insides of quote pairs
////////////////////////////////////////////////////////////////////////////////////////////
uint64_t quote_bits =
cmp_mask_against_input(input_lo, input_hi, doubleQuoteVec);
quote_bits = quote_bits & ~odd_ends;
uint64_t quote_mask = Sse2.X64.ConvertToUInt64(Pclmulqdq.CarrylessMultiply(
Vector128.Create(quote_bits, 0UL /*C# reversed*/), ffVec, 0));
uint32_t cnt = (uint32_t)hamming(structurals);
uint32_t next_base = @base + cnt;
while (structurals != 0)
{
base_ptr[@base + 0] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 1] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 2] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 3] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 4] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 5] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 6] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 7] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
@base += 8;
}
@base = next_base;
quote_mask ^= prev_iter_inside_quote;
prev_iter_inside_quote =
(uint64_t)((int64_t)quote_mask >>
63); // right shift of a signed value expected to be well-defined and standard compliant as of C++20, John Regher from Utah U. says this is fine code
var v_lo = Avx2.And(
Avx2.Shuffle(low_nibble_mask, input_lo),
Avx2.Shuffle(high_nibble_mask,
Avx2.And(Avx2.ShiftRightLogical(input_lo.AsUInt32(), 4).AsByte(),
vec7f)));
var v_hi = Avx2.And(
Avx2.Shuffle(low_nibble_mask, input_hi),
Avx2.Shuffle(high_nibble_mask,
Avx2.And(Avx2.ShiftRightLogical(input_hi.AsUInt32(), 4).AsByte(),
vec7f)));
var tmp_lo = Avx2.CompareEqual(
Avx2.And(v_lo, structural_shufti_mask), zeroBVec);
var tmp_hi = Avx2.CompareEqual(
Avx2.And(v_hi, structural_shufti_mask), zeroBVec);
uint64_t structural_res_0 = (uint32_t)Avx2.MoveMask(tmp_lo);
uint64_t structural_res_1 = (uint64_t)Avx2.MoveMask(tmp_hi);
structurals = ~(structural_res_0 | (structural_res_1 << 32));
var tmp_ws_lo = Avx2.CompareEqual(
Avx2.And(v_lo, whitespace_shufti_mask), zeroBVec);
var tmp_ws_hi = Avx2.CompareEqual(
Avx2.And(v_hi, whitespace_shufti_mask), zeroBVec);
uint64_t ws_res_0 = (uint32_t)Avx2.MoveMask(tmp_ws_lo);
uint64_t ws_res_1 = (uint64_t)Avx2.MoveMask(tmp_ws_hi);
uint64_t whitespace = ~(ws_res_0 | (ws_res_1 << 32));
// mask off anything inside quotes
structurals &= ~quote_mask;
// add the real quote bits back into our bitmask as well, so we can
// quickly traverse the strings we've spent all this trouble gathering
structurals |= quote_bits;
// Now, establish "pseudo-structural characters". These are non-whitespace
// characters that are (a) outside quotes and (b) have a predecessor that's
// either whitespace or a structural character. This means that subsequent
// passes will get a chance to encounter the first character of every string
// of non-whitespace and, if we're parsing an atom like true/false/null or a
// number we can stop at the first whitespace or structural character
// following it.
// a qualified predecessor is something that can happen 1 position before an
// psuedo-structural character
uint64_t pseudo_pred = structurals | whitespace;
uint64_t shifted_pseudo_pred = (pseudo_pred << 1) | prev_iter_ends_pseudo_pred;
prev_iter_ends_pseudo_pred = pseudo_pred >> 63;
uint64_t pseudo_structurals =
shifted_pseudo_pred & (~whitespace) & (~quote_mask);
structurals |= pseudo_structurals;
// now, we've used our close quotes all we need to. So let's switch them off
// they will be off in the quote mask and on in quote bits.
structurals &= ~(quote_bits & ~quote_mask);
//Console.WriteLine($"Iter: {idx}, satur: {structurals}");
//*(uint64_t *)(pj->structurals + idx / 8) = structurals;
}
////////////////
/// we use a giant copy-paste which is ugly.
/// but otherwise the string needs to be properly padded or else we
/// risk invalidating the UTF-8 checks.
////////////
if (idx < len)
{
uint8_t *tmpbuf = stackalloc uint8_t[64];
memset(tmpbuf, 0x20, 64);
memcpy(tmpbuf, buf + idx, len - idx);
Vector256 <byte> input_lo = Avx.LoadVector256(tmpbuf + 0);
Vector256 <byte> input_hi = Avx.LoadVector256(tmpbuf + 32);
////////////////////////////////////////////////////////////////////////////////////////////
// Step 1: detect odd sequences of backslashes
////////////////////////////////////////////////////////////////////////////////////////////
uint64_t bs_bits =
cmp_mask_against_input(input_lo, input_hi, slashVec);
uint64_t start_edges = bs_bits & ~(bs_bits << 1);
// flip lowest if we have an odd-length run at the end of the prior
// iteration
uint64_t even_start_mask = even_bits ^ prev_iter_ends_odd_backslash;
uint64_t even_starts = start_edges & even_start_mask;
uint64_t odd_starts = start_edges & ~even_start_mask;
uint64_t even_carries = bs_bits + even_starts;
uint64_t odd_carries;
// must record the carry-out of our odd-carries out of bit 63; this
// indicates whether the sense of any edge going to the next iteration
// should be flipped
//bool iter_ends_odd_backslash =
add_overflow(bs_bits, odd_starts, &odd_carries);
odd_carries |=
prev_iter_ends_odd_backslash; // push in bit zero as a potential end
// if we had an odd-numbered run at the
// end of the previous iteration
//prev_iter_ends_odd_backslash = iter_ends_odd_backslash ? 0x1ULL : 0x0ULL;
uint64_t even_carry_ends = even_carries & ~bs_bits;
uint64_t odd_carry_ends = odd_carries & ~bs_bits;
uint64_t even_start_odd_end = even_carry_ends & odd_bits;
uint64_t odd_start_even_end = odd_carry_ends & even_bits;
uint64_t odd_ends = even_start_odd_end | odd_start_even_end;
////////////////////////////////////////////////////////////////////////////////////////////
// Step 2: detect insides of quote pairs
////////////////////////////////////////////////////////////////////////////////////////////
uint64_t quote_bits =
cmp_mask_against_input(input_lo, input_hi, doubleQuoteVec);
quote_bits = quote_bits & ~odd_ends;
uint64_t quote_mask = (uint64_t)Sse2.X64.ConvertToInt64(Pclmulqdq.CarrylessMultiply(
Vector128.Create(quote_bits, 0UL /*C# reversed*/), ffVec, 0).AsInt64());
quote_mask ^= prev_iter_inside_quote;
//BUG? https://github.com/dotnet/coreclr/issues/22813
//quote_mask = 60;
//prev_iter_inside_quote = (uint64_t)((int64_t)quote_mask >> 63); // right shift of a signed value expected to be well-defined and standard compliant as of C++20
uint32_t cnt = (uint32_t)hamming(structurals);
uint32_t next_base = @base + cnt;
while (structurals != 0)
{
base_ptr[@base + 0] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 1] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 2] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 3] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 4] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 5] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 6] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 7] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
@base += 8;
}
@base = next_base;
// How do we build up a user traversable data structure
// first, do a 'shufti' to detect structural JSON characters
// they are { 0x7b } 0x7d : 0x3a [ 0x5b ] 0x5d , 0x2c
// these go into the first 3 buckets of the comparison (1/2/4)
// we are also interested in the four whitespace characters
// space 0x20, linefeed 0x0a, horizontal tab 0x09 and carriage return 0x0d
// these go into the next 2 buckets of the comparison (8/16)
var v_lo = Avx2.And(
Avx2.Shuffle(low_nibble_mask, input_lo),
Avx2.Shuffle(high_nibble_mask,
Avx2.And(Avx2.ShiftRightLogical(input_lo.AsUInt32(), 4).AsByte(),
vec7f)));
var v_hi = Avx2.And(
Avx2.Shuffle(low_nibble_mask, input_hi),
Avx2.Shuffle(high_nibble_mask,
Avx2.And(Avx2.ShiftRightLogical(input_hi.AsUInt32(), 4).AsByte(),
vec7f)));
var tmp_lo = Avx2.CompareEqual(
Avx2.And(v_lo, structural_shufti_mask), zeroBVec);
var tmp_hi = Avx2.CompareEqual(
Avx2.And(v_hi, structural_shufti_mask), zeroBVec);
uint64_t structural_res_0 = (uint32_t)Avx2.MoveMask(tmp_lo);
uint64_t structural_res_1 = (uint64_t)Avx2.MoveMask(tmp_hi);
structurals = ~(structural_res_0 | (structural_res_1 << 32));
// this additional mask and transfer is non-trivially expensive,
// unfortunately
var tmp_ws_lo = Avx2.CompareEqual(
Avx2.And(v_lo, whitespace_shufti_mask), zeroBVec);
var tmp_ws_hi = Avx2.CompareEqual(
Avx2.And(v_hi, whitespace_shufti_mask), zeroBVec);
uint64_t ws_res_0 = (uint32_t)Avx2.MoveMask(tmp_ws_lo);
uint64_t ws_res_1 = (uint64_t)Avx2.MoveMask(tmp_ws_hi);
uint64_t whitespace = ~(ws_res_0 | (ws_res_1 << 32));
// mask off anything inside quotes
structurals &= ~quote_mask;
// add the real quote bits back into our bitmask as well, so we can
// quickly traverse the strings we've spent all this trouble gathering
structurals |= quote_bits;
// Now, establish "pseudo-structural characters". These are non-whitespace
// characters that are (a) outside quotes and (b) have a predecessor that's
// either whitespace or a structural character. This means that subsequent
// passes will get a chance to encounter the first character of every string
// of non-whitespace and, if we're parsing an atom like true/false/null or a
// number we can stop at the first whitespace or structural character
// following it.
// a qualified predecessor is something that can happen 1 position before an
// psuedo-structural character
uint64_t pseudo_pred = structurals | whitespace;
uint64_t shifted_pseudo_pred = (pseudo_pred << 1) | prev_iter_ends_pseudo_pred;
prev_iter_ends_pseudo_pred = pseudo_pred >> 63;
uint64_t pseudo_structurals =
shifted_pseudo_pred & (~whitespace) & (~quote_mask);
structurals |= pseudo_structurals;
// now, we've used our close quotes all we need to. So let's switch them off
// they will be off in the quote mask and on in quote bits.
structurals &= ~(quote_bits & ~quote_mask);
//*(uint64_t *)(pj->structurals + idx / 8) = structurals;
idx += 64;
}
uint32_t cnt2 = (uint32_t)hamming(structurals);
uint32_t next_base2 = @base + cnt2;
while (structurals != 0)
{
base_ptr[@base + 0] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 1] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 2] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 3] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 4] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 5] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 6] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
base_ptr[@base + 7] = (uint32_t)idx - 64 + (uint32_t)trailingzeroes(structurals);
structurals = structurals & (structurals - 1);
@base += 8;
}
@base = next_base2;
pj->n_structural_indexes = @base;
if (base_ptr[pj->n_structural_indexes - 1] > len)
{
throw new InvalidOperationException("Internal bug");
}
if (len != base_ptr[pj->n_structural_indexes - 1])
{
// the string might not be NULL terminated, but we add a virtual NULL ending character.
base_ptr[pj->n_structural_indexes++] = (uint32_t)len;
}
base_ptr[pj->n_structural_indexes] = 0; // make it safe to dereference one beyond this array
return(true);
}
public static bool unified_machine(uint8_t *buf, size_t len, ParsedJson *pj)
{
uint32_t i = 0; // index of the structural character (0,1,2,3...)
uint32_t idx; // location of the structural character in the input (buf)
uint8_t c; // used to track the (structural) character we are looking at, updated
// by UPDATE_CHAR macro
uint32_t depth = 0; // could have an arbitrary starting depth
pj->init();
if (pj->bytecapacity < len)
{
Debug.Write("insufficient capacity\n");
return(false);
}
// this macro reads the next structural character, updating idx, i and c.
//C#: expanded directly everywhere
//void UPDATE_CHAR()
//{
// idx = pj->structural_indexes[i++];
// c = buf[idx];
//}
pj->ret_address[depth] = (bytechar)'s';
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->write_tape(0, (byte)'r'); // r for root, 0 is going to get overwritten
// the root is used, if nothing else, to capture the size of the tape
depth++; // everything starts at depth = 1, depth = 0 is just for the root, the root may contain an object, an array or something else.
if (depth > pj->depthcapacity)
{
goto fail;
}
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
switch (c)
{
case (uint8_t)'{':
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->ret_address[depth] = (bytechar)'s';
depth++;
if (depth > pj->depthcapacity)
{
goto fail;
}
pj->write_tape(0, c); // strangely, moving this to object_begin slows things down
goto object_begin;
case (uint8_t)'[':
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->ret_address[depth] = (bytechar)'s';
depth++;
if (depth > pj->depthcapacity)
{
goto fail;
}
pj->write_tape(0, c);
goto array_begin;
// A JSON text is a serialized value. Note that certain previous
// specifications of JSON constrained a JSON text to be an object or an
// array. Implementations that generate only objects or arrays where a
// JSON text is called for will be interoperable in the sense that all
// implementations will accept these as conforming JSON texts.
// https://tools.ietf.org/html/rfc8259
#if SIMDJSON_ALLOWANYTHINGINROOT
case (uint8_t)'"':
{
if (!parse_string(buf, len, pj, depth, idx))
{
goto fail;
}
break;
}
case (uint8_t)'t':
{
// we need to make a copy to make sure that the string is NULL terminated.
// this only applies to the JSON document made solely of the true value.
// this will almost never be called in practice
bytechar *copy = stackalloc bytechar[(int)(len + SIMDJSON_PADDING)];
if (copy == null)
{
goto fail;
}
memcpy(copy, buf, len);
copy[len] = (bytechar)'\0';
if (!is_valid_true_atom((uint8_t *)copy + idx))
{
//free(copy);
goto fail;
}
//free(copy);
pj->write_tape(0, c);
break;
}
case (uint8_t)'f':
{
// we need to make a copy to make sure that the string is NULL terminated.
// this only applies to the JSON document made solely of the false value.
// this will almost never be called in practice
bytechar *copy = stackalloc bytechar[(int)(len + SIMDJSON_PADDING)];
if (copy == null)
{
goto fail;
}
memcpy(copy, buf, len);
copy[len] = (bytechar)'\0';
if (!is_valid_false_atom((uint8_t *)copy + idx))
{
//free(copy);
goto fail;
}
//free(copy);
pj->write_tape(0, c);
break;
}
case (uint8_t)'n':
{
// we need to make a copy to make sure that the string is NULL terminated.
// this only applies to the JSON document made solely of the null value.
// this will almost never be called in practice
bytechar *copy = stackalloc bytechar[(int)(len + SIMDJSON_PADDING)];
if (copy == null)
{
goto fail;
}
memcpy(copy, buf, len);
copy[len] = (bytechar)'\0';
if (!is_valid_null_atom((uint8_t *)copy + idx))
{
//free(copy);
goto fail;
}
//free(copy);
pj->write_tape(0, c);
break;
}
case (uint8_t)'0':
case (uint8_t)'1':
case (uint8_t)'2':
case (uint8_t)'3':
case (uint8_t)'4':
case (uint8_t)'5':
case (uint8_t)'6':
case (uint8_t)'7':
case (uint8_t)'8':
case (uint8_t)'9':
{
// we need to make a copy to make sure that the string is NULL terminated.
// this is done only for JSON documents made of a sole number
// this will almost never be called in practice
bytechar *copy = stackalloc bytechar[(int)(len + SIMDJSON_PADDING)];
if (copy == null)
{
goto fail;
}
memcpy(copy, buf, len);
copy[len] = (bytechar)'\0';
if (!parse_number((uint8_t *)copy, pj, idx, false))
{
//free(copy);
goto fail;
}
//free(copy);
break;
}
case (uint8_t)'-':
{
// we need to make a copy to make sure that the string is NULL terminated.
// this is done only for JSON documents made of a sole number
// this will almost never be called in practice
bytechar *copy = stackalloc bytechar[(int)(len + SIMDJSON_PADDING)];
if (copy == null)
{
goto fail;
}
memcpy(copy, buf, len);
copy[len] = (bytechar)'\0';
if (!parse_number((uint8_t *)copy, pj, idx, true))
{
//free(copy);
goto fail;
}
//free(copy);
break;
}
#endif // ALLOWANYTHINGINROOT
default:
goto fail;
}
start_continue:
// the string might not be NULL terminated.
if (i + 1 == pj->n_structural_indexes)
{
goto succeed;
}
else
{
goto fail;
}
////////////////////////////// OBJECT STATES /////////////////////////////
object_begin:
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
switch (c)
{
case (uint8_t)'"':
{
if (!parse_string(buf, len, pj, depth, idx))
{
goto fail;
}
goto object_key_state;
}
case (uint8_t)'}':
goto scope_end; // could also go to object_continue
default:
goto fail;
}
object_key_state:
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
if (c != ':')
{
goto fail;
}
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
switch (c)
{
case (uint8_t)'"':
{
if (!parse_string(buf, len, pj, depth, idx))
{
goto fail;
}
break;
}
case (uint8_t)'t':
if (!is_valid_true_atom(buf + idx))
{
goto fail;
}
pj->write_tape(0, c);
break;
case (uint8_t)'f':
if (!is_valid_false_atom(buf + idx))
{
goto fail;
}
pj->write_tape(0, c);
break;
case (uint8_t)'n':
if (!is_valid_null_atom(buf + idx))
{
goto fail;
}
pj->write_tape(0, c);
break;
case (uint8_t)'0':
case (uint8_t)'1':
case (uint8_t)'2':
case (uint8_t)'3':
case (uint8_t)'4':
case (uint8_t)'5':
case (uint8_t)'6':
case (uint8_t)'7':
case (uint8_t)'8':
case (uint8_t)'9':
{
if (!parse_number(buf, pj, idx, false))
{
goto fail;
}
break;
}
case (uint8_t)'-':
{
if (!parse_number(buf, pj, idx, true))
{
goto fail;
}
break;
}
case (uint8_t)'{':
{
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->write_tape(0, c); // here the compilers knows what c is so this gets optimized
// we have not yet encountered } so we need to come back for it
pj->ret_address[depth] = (bytechar)'o';
// we found an object inside an object, so we need to increment the depth
depth++;
if (depth > pj->depthcapacity)
{
goto fail;
}
goto object_begin;
}
case (uint8_t)'[':
{
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->write_tape(0, c); // here the compilers knows what c is so this gets optimized
// we have not yet encountered } so we need to come back for it
pj->ret_address[depth] = (bytechar)'o';
// we found an array inside an object, so we need to increment the depth
depth++;
if (depth > pj->depthcapacity)
{
goto fail;
}
goto array_begin;
}
default:
goto fail;
}
object_continue:
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
switch (c)
{
case (uint8_t)',':
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
if (c != (uint8_t)'"')
{
goto fail;
}
else
{
if (!parse_string(buf, len, pj, depth, idx))
{
goto fail;
}
goto object_key_state;
}
case (uint8_t)'}':
goto scope_end;
default:
goto fail;
}
////////////////////////////// COMMON STATE /////////////////////////////
scope_end:
// write our tape location to the header scope
depth--;
pj->write_tape(pj->containing_scope_offset[depth], c);
pj->annotate_previousloc(pj->containing_scope_offset[depth],
pj->get_current_loc());
// goto saved_state
if (pj->ret_address[depth] == (uint8_t)'a')
{
goto array_continue;
}
else if (pj->ret_address[depth] == (uint8_t)'o')
{
goto object_continue;
}
else
{
goto start_continue;
}
////////////////////////////// ARRAY STATES /////////////////////////////
array_begin:
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
if (c == ']')
{
goto scope_end; // could also go to array_continue
}
main_array_switch:
// we call update char on all paths in, so we can peek at c on the
// on paths that can accept a close square brace (post-, and at start)
switch (c)
{
case (uint8_t)'"':
{
if (!parse_string(buf, len, pj, depth, idx))
{
goto fail;
}
break;
}
case (uint8_t)'t':
if (!is_valid_true_atom(buf + idx))
{
goto fail;
}
pj->write_tape(0, c);
break;
case (uint8_t)'f':
if (!is_valid_false_atom(buf + idx))
{
goto fail;
}
pj->write_tape(0, c);
break;
case (uint8_t)'n':
if (!is_valid_null_atom(buf + idx))
{
goto fail;
}
pj->write_tape(0, c);
break; // goto array_continue;
case (uint8_t)'0':
case (uint8_t)'1':
case (uint8_t)'2':
case (uint8_t)'3':
case (uint8_t)'4':
case (uint8_t)'5':
case (uint8_t)'6':
case (uint8_t)'7':
case (uint8_t)'8':
case (uint8_t)'9':
{
if (!parse_number(buf, pj, idx, false))
{
goto fail;
}
break; // goto array_continue;
}
case (uint8_t)'-':
{
if (!parse_number(buf, pj, idx, true))
{
goto fail;
}
break; // goto array_continue;
}
case (uint8_t)'{':
{
// we have not yet encountered ] so we need to come back for it
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->write_tape(0, c); // here the compilers knows what c is so this gets optimized
pj->ret_address[depth] = (bytechar)'a';
// we found an object inside an array, so we need to increment the depth
depth++;
if (depth > pj->depthcapacity)
{
goto fail;
}
goto object_begin;
}
case (uint8_t)'[':
{
// we have not yet encountered ] so we need to come back for it
pj->containing_scope_offset[depth] = pj->get_current_loc();
pj->write_tape(0, c); // here the compilers knows what c is so this gets optimized
pj->ret_address[depth] = (bytechar)'a';
// we found an array inside an array, so we need to increment the depth
depth++;
if (depth > pj->depthcapacity)
{
goto fail;
}
goto array_begin;
}
default:
goto fail;
}
array_continue:
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
switch (c)
{
case (uint8_t)',':
//UPDATE_CHAR():
idx = pj->structural_indexes[i++];
c = buf[idx];
goto main_array_switch;
case (uint8_t)']':
goto scope_end;
default:
goto fail;
}
////////////////////////////// FINAL STATES /////////////////////////////
succeed:
depth--;
if (depth != 0)
{
throw new InvalidOperationException("internal bug");
}
if (pj->containing_scope_offset[depth] != 0)
{
throw new InvalidOperationException("internal bug");
}
pj->annotate_previousloc(pj->containing_scope_offset[depth],
pj->get_current_loc());
pj->write_tape(pj->containing_scope_offset[depth], (byte)'r'); // r is root
pj->isvalid = true;
return(true);
fail:
return(false);
}
