--- JSON-XS/XS.xs 2008/03/19 13:44:43 1.73 +++ JSON-XS/XS.xs 2008/06/03 06:43:45 1.87 @@ -6,6 +6,7 @@ #include #include #include +#include #include #if defined(__BORLANDC__) || defined(_MSC_VER) @@ -18,6 +19,8 @@ # define UTF8_MAXBYTES 13 #endif +#define IVUV_MAXCHARS (sizeof (UV) * CHAR_BIT * 28 / 93 + 2) + #define F_ASCII 0x00000001UL #define F_LATIN1 0x00000002UL #define F_UTF8 0x00000004UL @@ -30,18 +33,10 @@ #define F_ALLOW_BLESSED 0x00000400UL #define F_CONV_BLESSED 0x00000800UL #define F_RELAXED 0x00001000UL - -#define F_MAXDEPTH 0xf8000000UL -#define S_MAXDEPTH 27 -#define F_MAXSIZE 0x01f00000UL -#define S_MAXSIZE 20 +#define F_ALLOW_UNKNOWN 0x00002000UL #define F_HOOK 0x00080000UL // some hooks exist, so slow-path processing -#define DEC_DEPTH(flags) (1UL << ((flags & F_MAXDEPTH) >> S_MAXDEPTH)) -#define DEC_SIZE(flags) (1UL << ((flags & F_MAXSIZE ) >> S_MAXSIZE )) - #define F_PRETTY F_INDENT | F_SPACE_BEFORE | F_SPACE_AFTER -#define F_DEFAULT (9UL << S_MAXDEPTH) #define INIT_SIZE 32 // initial scalar size to be allocated #define INDENT_STEP 3 // spaces per indentation level @@ -66,6 +61,8 @@ ((unsigned type)((unsigned type)(val) - (unsigned type)(beg)) \ <= (unsigned type)((unsigned type)(end) - (unsigned type)(beg))) +#define ERR_NESTING_EXCEEDED "json text or perl structure exceeds maximum nesting level (max_depth set too low?)" + #ifdef USE_ITHREADS # define JSON_SLOW 1 # define JSON_STASH (json_stash ? json_stash : gv_stashpv ("JSON::XS", 1)) @@ -77,19 +74,56 @@ static HV *json_stash, *json_boolean_stash; // JSON::XS:: static SV *json_true, *json_false; +enum { + INCR_M_WS = 0, // initial whitespace skipping, must be 0 + INCR_M_STR, // inside string + INCR_M_BS, // inside backslash + INCR_M_JSON // outside anything, count nesting +}; + +#define INCR_DONE(json) (!(json)->incr_nest && (json)->incr_mode == INCR_M_JSON) + typedef struct { U32 flags; + U32 max_depth; + STRLEN max_size; + SV *cb_object; HV *cb_sk_object; + + // for the incremental parser + SV *incr_text; // the source text so far + STRLEN incr_pos; // the current offset into the text + unsigned char incr_nest; // {[]}-nesting level + unsigned char incr_mode; } JSON; +INLINE void +json_init (JSON *json) +{ + Zero (json, 1, JSON); + json->max_depth = 512; +} + ///////////////////////////////////////////////////////////////////////////// // utility functions +INLINE SV * +get_bool (const char *name) +{ + SV *sv = get_sv (name, 1); + + SvREADONLY_on (sv); + SvREADONLY_on (SvRV (sv)); + + return sv; +} + INLINE void shrink (SV *sv) { sv_utf8_downgrade (sv, 1); + if (SvLEN (sv) > SvCUR (sv) + 1) { #ifdef SvPV_shrink_to_cur @@ -125,13 +159,20 @@ INLINE unsigned char * encode_utf8 (unsigned char *s, UV ch) { - if (ch <= 0x7FF) - { - *s++ = (ch >> 6) | 0xc0; - *s++ = (ch & 0x3f) | 0x80; - } - else - s = uvuni_to_utf8_flags (s, ch, 0); + if (expect_false (ch < 0x000080)) + *s++ = ch; + else if (expect_true (ch < 0x000800)) + *s++ = 0xc0 | ( ch >> 6), + *s++ = 0x80 | ( ch & 0x3f); + else if ( ch < 0x010000) + *s++ = 0xe0 | ( ch >> 12), + *s++ = 0x80 | ((ch >> 6) & 0x3f), + *s++ = 0x80 | ( ch & 0x3f); + else if ( ch < 0x110000) + *s++ = 0xf0 | ( ch >> 18), + *s++ = 0x80 | ((ch >> 12) & 0x3f), + *s++ = 0x80 | ((ch >> 6) & 0x3f), + *s++ = 0x80 | ( ch & 0x3f); return s; } @@ -147,7 +188,6 @@ SV *sv; // result scalar JSON json; U32 indent; // indentation level - U32 maxdepth; // max. indentation/recursion level UV limit; // escape character values >= this value when encoding } enc_t; @@ -229,9 +269,9 @@ if (uch < 0x80/*0x20*/ || uch >= enc->limit) { - if (uch > 0xFFFFUL) + if (uch >= 0x10000UL) { - if (uch > 0x10FFFFUL) + if (uch >= 0x110000UL) croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch); need (enc, len += 11); @@ -330,8 +370,8 @@ { int i, len = av_len (av); - if (enc->indent >= enc->maxdepth) - croak ("data structure too deep (hit recursion limit)"); + if (enc->indent >= enc->json.max_depth) + croak (ERR_NESTING_EXCEEDED); encode_ch (enc, '['); @@ -415,10 +455,9 @@ encode_hv (enc_t *enc, HV *hv) { HE *he; - int count; - if (enc->indent >= enc->maxdepth) - croak ("data structure too deep (hit recursion limit)"); + if (enc->indent >= enc->json.max_depth) + croak (ERR_NESTING_EXCEEDED); encode_ch (enc, '{'); @@ -609,10 +648,14 @@ encode_str (enc, "true", 4, 0); else if (len == 1 && *pv == '0') encode_str (enc, "false", 5, 0); + else if (enc->json.flags & F_ALLOW_UNKNOWN) + encode_str (enc, "null", 4, 0); else croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1", SvPV_nolen (sv_2mortal (newRV_inc (sv)))); } + else if (enc->json.flags & F_ALLOW_UNKNOWN) + encode_str (enc, "null", 4, 0); else croak ("encountered %s, but JSON can only represent references to arrays or hashes", SvPV_nolen (sv_2mortal (newRV_inc (sv)))); @@ -640,21 +683,16 @@ } else if (SvIOKp (sv)) { - // we assume we can always read an IV as a UV - if (SvUV (sv) & ~(UV)0x7fff) - { - // large integer, use the (rather slow) snprintf way. - need (enc, sizeof (UV) * 3); - enc->cur += - SvIsUV(sv) - ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv)) - : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv)); - } - else + // we assume we can always read an IV as a UV and vice versa + // we assume two's complement + // we assume no aliasing issues in the union + if (SvIsUV (sv) ? SvUVX (sv) <= 59000 + : SvIVX (sv) <= 59000 && SvIVX (sv) >= -59000) { // optimise the "small number case" // code will likely be branchless and use only a single multiplication - I32 i = SvIV (sv); + // works for numbers up to 59074 + I32 i = SvIVX (sv); U32 u; char digit, nz = 0; @@ -670,17 +708,26 @@ // and multiplying by 5 while moving the decimal point one to the right, // resulting in a net multiplication by 10. // we always write the digit to memory but conditionally increment - // the pointer, to ease the usage of conditional move instructions. - digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5; - digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5; - digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5; - digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5; + // the pointer, to enable the use of conditional move instructions. + digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffffUL) * 5; + digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffffUL) * 5; + digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffffUL) * 5; + digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffffUL) * 5; digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0' } + else + { + // large integer, use the (rather slow) snprintf way. + need (enc, IVUV_MAXCHARS); + enc->cur += + SvIsUV(sv) + ? snprintf (enc->cur, IVUV_MAXCHARS, "%"UVuf, (UV)SvUVX (sv)) + : snprintf (enc->cur, IVUV_MAXCHARS, "%"IVdf, (IV)SvIVX (sv)); + } } else if (SvROK (sv)) encode_rv (enc, SvRV (sv)); - else if (!SvOK (sv)) + else if (!SvOK (sv) || enc->json.flags & F_ALLOW_UNKNOWN) encode_str (enc, "null", 4, 0); else croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this", @@ -700,10 +747,9 @@ enc.cur = SvPVX (enc.sv); enc.end = SvEND (enc.sv); enc.indent = 0; - enc.maxdepth = DEC_DEPTH (enc.json.flags); enc.limit = enc.json.flags & F_ASCII ? 0x000080UL : enc.json.flags & F_LATIN1 ? 0x000100UL - : 0x10FFFFUL; + : 0x110000UL; SvPOK_only (enc.sv); encode_sv (&enc, scalar); @@ -777,7 +823,7 @@ ++dec->cur; \ SE -#define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)") +#define DEC_INC_DEPTH if (++dec->depth > dec->json.max_depth) ERR (ERR_NESTING_EXCEEDED) #define DEC_DEC_DEPTH --dec->depth static SV *decode_sv (dec_t *dec); @@ -891,7 +937,7 @@ ERR ("illegal backslash escape sequence in string"); } } - else if (expect_true (ch >= 0x20 && ch <= 0x7f)) + else if (expect_true (ch >= 0x20 && ch < 0x80)) *cur++ = ch; else if (ch >= 0x80) { @@ -1159,7 +1205,7 @@ for (;;) { - // the >= 0x80 is true on most architectures + // the >= 0x80 is false on most architectures if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\') { // slow path, back up and use decode_str @@ -1317,9 +1363,9 @@ { dec->cur += 4; #if JSON_SLOW - json_true = get_sv ("JSON::XS::true", 1); SvREADONLY_on (json_true); + json_true = get_bool ("JSON::XS::true"); #endif - return SvREFCNT_inc (json_true); + return newSVsv (json_true); } else ERR ("'true' expected"); @@ -1331,9 +1377,9 @@ { dec->cur += 5; #if JSON_SLOW - json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false); + json_false = get_bool ("JSON::XS::false"); #endif - return SvREFCNT_inc (json_false); + return newSVsv (json_false); } else ERR ("'false' expected"); @@ -1361,18 +1407,25 @@ } static SV * -decode_json (SV *string, JSON *json, UV *offset_return) +decode_json (SV *string, JSON *json, STRLEN *offset_return) { dec_t dec; - UV offset; + STRLEN offset; SV *sv; SvGETMAGIC (string); SvUPGRADE (string, SVt_PV); - if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags)) + /* work around a bug in perl 5.10, which causes SvCUR to fail an + * assertion with -DDEBUGGING, although SvCUR is documented to + * return the xpv_cur field which certainly exists after upgrading. + * according to nicholas clark, calling SvPOK fixes this. + */ + SvPOK (string); + + if (SvCUR (string) > json->max_size && json->max_size) croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu", - (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags)); + (unsigned long)SvCUR (string), (unsigned long)json->max_size); if (json->flags & F_UTF8) sv_utf8_downgrade (string, 0); @@ -1381,12 +1434,11 @@ SvGROW (string, SvCUR (string) + 1); // should basically be a NOP - dec.json = *json; - dec.cur = SvPVX (string); - dec.end = SvEND (string); - dec.err = 0; - dec.depth = 0; - dec.maxdepth = DEC_DEPTH (dec.json.flags); + dec.json = *json; + dec.cur = SvPVX (string); + dec.end = SvEND (string); + dec.err = 0; + dec.depth = 0; if (dec.json.cb_object || dec.json.cb_sk_object) dec.json.flags |= F_HOOK; @@ -1447,6 +1499,123 @@ } ///////////////////////////////////////////////////////////////////////////// +// incremental parser + +static void +incr_parse (JSON *self) +{ + const char *p = SvPVX (self->incr_text) + self->incr_pos; + + for (;;) + { + //printf ("loop pod %d *p<%c><%s>, mode %d nest %d\n", p - SvPVX (self->incr_text), *p, p, self->incr_mode, self->incr_nest);//D + switch (self->incr_mode) + { + // only used for intiial whitespace skipping + case INCR_M_WS: + for (;;) + { + if (*p > 0x20) + { + self->incr_mode = INCR_M_JSON; + goto incr_m_json; + } + else if (!*p) + goto interrupt; + + ++p; + } + + // skip a single char inside a string (for \\-processing) + case INCR_M_BS: + if (!*p) + goto interrupt; + + ++p; + self->incr_mode = INCR_M_STR; + goto incr_m_str; + + // inside a string + case INCR_M_STR: + incr_m_str: + for (;;) + { + if (*p == '"') + { + ++p; + self->incr_mode = INCR_M_JSON; + + if (!self->incr_nest) + goto interrupt; + + goto incr_m_json; + } + else if (*p == '\\') + { + ++p; // "virtually" consumes character after \ + + if (!*p) // if at end of string we have to switch modes + { + self->incr_mode = INCR_M_BS; + goto interrupt; + } + } + else if (!*p) + goto interrupt; + + ++p; + } + + // after initial ws, outside string + case INCR_M_JSON: + incr_m_json: + for (;;) + { + switch (*p++) + { + case 0: + --p; + goto interrupt; + + case 0x09: + case 0x0a: + case 0x0d: + case 0x20: + if (!self->incr_nest) + { + --p; // do not eat the whitespace, let the next round do it + goto interrupt; + } + break; + + case '"': + self->incr_mode = INCR_M_STR; + goto incr_m_str; + + case '[': + case '{': + if (++self->incr_nest > self->max_depth) + croak (ERR_NESTING_EXCEEDED); + break; + + case ']': + case '}': + if (!--self->incr_nest) + goto interrupt; + } + } + } + + modechange: + ; + } + +interrupt: + self->incr_pos = p - SvPVX (self->incr_text); + //printf ("return pos %d mode %d nest %d\n", self->incr_pos, self->incr_mode, self->incr_nest);//D +} + +///////////////////////////////////////////////////////////////////////////// // XS interface functions MODULE = JSON::XS PACKAGE = JSON::XS @@ -1465,8 +1634,8 @@ json_stash = gv_stashpv ("JSON::XS" , 1); json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1); - json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true ); - json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false); + json_true = get_bool ("JSON::XS::true"); + json_false = get_bool ("JSON::XS::false"); } PROTOTYPES: DISABLE @@ -1481,8 +1650,7 @@ { SV *pv = NEWSV (0, sizeof (JSON)); SvPOK_only (pv); - Zero (SvPVX (pv), 1, JSON); - ((JSON *)SvPVX (pv))->flags = F_DEFAULT; + json_init ((JSON *)SvPVX (pv)); XPUSHs (sv_2mortal (sv_bless ( newRV_noinc (pv), strEQ (klass, "JSON::XS") ? JSON_STASH : gv_stashpv (klass, 1) @@ -1504,6 +1672,7 @@ allow_blessed = F_ALLOW_BLESSED convert_blessed = F_CONV_BLESSED relaxed = F_RELAXED + allow_unknown = F_ALLOW_UNKNOWN PPCODE: { if (enable) @@ -1528,49 +1697,29 @@ get_allow_blessed = F_ALLOW_BLESSED get_convert_blessed = F_CONV_BLESSED get_relaxed = F_RELAXED + get_allow_unknown = F_ALLOW_UNKNOWN PPCODE: XPUSHs (boolSV (self->flags & ix)); -void max_depth (JSON *self, UV max_depth = 0x80000000UL) +void max_depth (JSON *self, U32 max_depth = 0x80000000UL) PPCODE: -{ - UV log2 = 0; - - if (max_depth > 0x80000000UL) max_depth = 0x80000000UL; - - while ((1UL << log2) < max_depth) - ++log2; - - self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH); - + self->max_depth = max_depth; XPUSHs (ST (0)); -} U32 get_max_depth (JSON *self) CODE: - RETVAL = DEC_DEPTH (self->flags); + RETVAL = self->max_depth; OUTPUT: RETVAL -void max_size (JSON *self, UV max_size = 0) +void max_size (JSON *self, U32 max_size = 0) PPCODE: -{ - UV log2 = 0; - - if (max_size > 0x80000000UL) max_size = 0x80000000UL; - if (max_size == 1) max_size = 2; - - while ((1UL << log2) < max_size) - ++log2; - - self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE); - + self->max_size = max_size; XPUSHs (ST (0)); -} int get_max_size (JSON *self) CODE: - RETVAL = DEC_SIZE (self->flags); + RETVAL = self->max_size; OUTPUT: RETVAL @@ -1616,30 +1765,132 @@ void decode_prefix (JSON *self, SV *jsonstr) PPCODE: { - UV offset; + STRLEN offset; EXTEND (SP, 2); PUSHs (decode_json (jsonstr, self, &offset)); PUSHs (sv_2mortal (newSVuv (offset))); } +void incr_parse (JSON *self, SV *jsonstr = 0) + PPCODE: +{ + if (!self->incr_text) + self->incr_text = newSVpvn ("", 0); + + // append data, if any + if (jsonstr) + { + if (SvUTF8 (jsonstr) && !SvUTF8 (self->incr_text)) + { + /* utf-8-ness differs, need to upgrade */ + sv_utf8_upgrade (self->incr_text); + + if (self->incr_pos) + self->incr_pos = utf8_hop ((U8 *)SvPVX (self->incr_text), self->incr_pos) + - (U8 *)SvPVX (self->incr_text); + } + + { + STRLEN len; + const char *str = SvPV (jsonstr, len); + SvGROW (self->incr_text, SvCUR (self->incr_text) + len + 1); + Move (str, SvEND (self->incr_text), len, char); + SvCUR_set (self->incr_text, SvCUR (self->incr_text) + len); + *SvEND (self->incr_text) = 0; // this should basically be a nop, too, but make sure it's there + } + } + + if (GIMME_V != G_VOID) + do + { + STRLEN offset; + + if (!INCR_DONE (self)) + { + incr_parse (self); + + if (self->incr_pos > self->max_size && self->max_size) + croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu", + (unsigned long)self->incr_pos, (unsigned long)self->max_size); + + if (!INCR_DONE (self)) + break; + } + + XPUSHs (decode_json (self->incr_text, self, &offset)); + + sv_chop (self->incr_text, SvPV_nolen (self->incr_text) + offset); + self->incr_pos -= offset; + self->incr_nest = 0; + self->incr_mode = 0; + } + while (GIMME_V == G_ARRAY); +} + +SV *incr_text (JSON *self) + ATTRS: lvalue + CODE: +{ + if (self->incr_pos) + croak ("incr_text can not be called when the incremental parser already started parsing"); + + RETVAL = self->incr_text ? SvREFCNT_inc (self->incr_text) : &PL_sv_undef; +} + OUTPUT: + RETVAL + +void incr_skip (JSON *self) + CODE: +{ + if (self->incr_pos) + { + sv_chop (self->incr_text, SvPV_nolen (self->incr_text) + self->incr_pos); + self->incr_pos = 0; + self->incr_nest = 0; + self->incr_mode = 0; + } +} + +void incr_reset (JSON *self) + CODE: +{ + SvREFCNT_dec (self->incr_text); + self->incr_text = 0; + self->incr_pos = 0; + self->incr_nest = 0; + self->incr_mode = 0; +} + void DESTROY (JSON *self) CODE: SvREFCNT_dec (self->cb_sk_object); SvREFCNT_dec (self->cb_object); + SvREFCNT_dec (self->incr_text); PROTOTYPES: ENABLE void encode_json (SV *scalar) + ALIAS: + to_json_ = 0 + encode_json = F_UTF8 PPCODE: { - JSON json = { F_DEFAULT | F_UTF8 }; + JSON json; + json_init (&json); + json.flags |= ix; XPUSHs (encode_json (scalar, &json)); } void decode_json (SV *jsonstr) + ALIAS: + from_json_ = 0 + decode_json = F_UTF8 PPCODE: { - JSON json = { F_DEFAULT | F_UTF8 }; + JSON json; + json_init (&json); + json.flags |= ix; XPUSHs (decode_json (jsonstr, &json, 0)); } +