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622f0da9cbf13fa6e8292fbb792cbb6d3ef7df87
cld2/internal/getonescriptspan.cc
dsites@google.com 622f0da9cb Add missing test for off the end 
git-svn-id: https://cld2.googlecode.com/svn/trunk@74 b252ecd4-b096-bf77-eb8e-91563289f87e
2013-08-25 17:14:42 +00:00

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38 KiB
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// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Author: dsites@google.com (Dick Sites)
//
#include "getonescriptspan.h"
#include <sys/time.h> // for gettimeofday
#include <string.h>
#include "fixunicodevalue.h"
#include "lang_script.h"
#include "port.h"
#include "utf8statetable.h"
#include "utf8prop_lettermarkscriptnum.h"
#include "utf8repl_lettermarklower.h"
#include "utf8scannot_lettermarkspecial.h"
namespace CLD2 {
// Alphabetical order for binary search, from
// generated_entities.cc
extern const int kNameToEntitySize;
extern const CharIntPair kNameToEntity[];
static const int kMaxUpToWordBoundary = 50; // span < this make longer,
// else make shorter
static const int kMaxAdvanceToWordBoundary = 10; // +/- this many bytes
// to round to word boundary,
// direction above
static const char kSpecialSymbol[256] = { // true for < > &
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,1,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,1,0,1,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
};
#define LT 0 // <
#define GT 1 // >
#define EX 2 // !
#define HY 3 // -
#define QU 4 // "
#define AP 5 // '
#define SL 6 // /
#define S_ 7
#define C_ 8
#define R_ 9
#define I_ 10
#define P_ 11
#define T_ 12
#define Y_ 13
#define L_ 14
#define E_ 15
#define CR 16 // <cr> or <lf>
#define NL 17 // non-letter: ASCII whitespace, digit, punctuation
#define PL 18 // possible letter, incl. &
#define xx 19 // <unused>
// Map byte to one of ~20 interesting categories for cheap tag parsing
static const uint8 kCharToSub[256] = {
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,CR,NL, NL,CR,NL,NL,
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
NL,EX,QU,NL, NL,NL,PL,AP, NL,NL,NL,NL, NL,HY,NL,SL,
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, LT,NL,GT,NL,
PL,PL,PL,C_, PL,E_,PL,PL, PL,I_,PL,PL, L_,PL,PL,PL,
P_,PL,R_,S_, T_,PL,PL,PL, PL,Y_,PL,NL, NL,NL,NL,NL,
PL,PL,PL,C_, PL,E_,PL,PL, PL,I_,PL,PL, L_,PL,PL,PL,
P_,PL,R_,S_, T_,PL,PL,PL, PL,Y_,PL,NL, NL,NL,NL,NL,
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
};
#undef LT
#undef GT
#undef EX
#undef HY
#undef QU
#undef AP
#undef SL
#undef S_
#undef C_
#undef R_
#undef I_
#undef P_
#undef T_
#undef Y_
#undef L_
#undef E_
#undef CR
#undef NL
#undef PL
#undef xx
#define OK 0
#define X_ 1
static const int kMaxExitStateLettersMarksOnly = 1;
static const int kMaxExitStateAllText = 2;
// State machine to do cheap parse of non-letter strings incl. tags
// advances <tag>
// | |
// advances <tag> ... </tag> for <script> <style>
// | |
// advances <!-- ... <tag> ... -->
// | |
// advances <tag
// || (0)
// advances <tag <tag2>
// || (0)
//
// We start in state [0] at a non-letter and make at least one transition
// When scanning for just letters, arriving back at state [0] or [1] exits
// the state machine.
// When scanning for any non-tag text, arriving at state [2] also exits
static const uint8 kTagParseTbl_0[] = {
// < > ! - " ' / S C R I P T Y L E CR NL PL xx
3, 2, 2, 2, 2, 2, 2,OK, OK,OK,OK,OK, OK,OK,OK,OK, 2, 2,OK,X_, // [0] OK exit state
X_,X_,X_,X_, X_,X_,X_,X_, X_,X_,X_,X_, X_,X_,X_,X_, X_,X_,X_,X_, // [1] error exit state
3, 2, 2, 2, 2, 2, 2,OK, OK,OK,OK,OK, OK,OK,OK,OK, 2, 2,OK,X_, // [2] NL* [exit state]
X_, 2, 4, 9, 10,11, 9,13, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,X_, // [3] <
X_, 2, 9, 5, 10,11, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,X_, // [4] <!
X_, 2, 9, 6, 10,11, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,X_, // [5] <!-
6, 6, 6, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,X_, // [6] <!--.*
6, 6, 6, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,X_, // [7] <!--.*-
6, 2, 6, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,X_, // [8] <!--.*--
X_, 2, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,X_, // [9] <.*
10,10,10,10, 9,10,10,10, 10,10,10,10, 10,10,10,10, 12,10,10,X_, // [10] <.*"
11,11,11,11, 11, 9,11,11, 11,11,11,11, 11,11,11,11, 12,11,11,X_, // [11] <.*'
X_, 2,12,12, 12,12,12,12, 12,12,12,12, 12,12,12,12, 12,12,12,X_, // [12] <.* no " '
// < > ! - " ' / S C R I P T Y L E CR NL PL xx
X_, 2, 9, 9, 10,11, 9, 9, 14, 9, 9, 9, 28, 9, 9, 9, 9, 9, 9,X_, // [13] <S
X_, 2, 9, 9, 10,11, 9, 9, 9,15, 9, 9, 9, 9, 9, 9, 9, 9, 9,X_, // [14] <SC
X_, 2, 9, 9, 10,11, 9, 9, 9, 9,16, 9, 9, 9, 9, 9, 9, 9, 9,X_, // [15] <SCR
X_, 2, 9, 9, 10,11, 9, 9, 9, 9, 9,17, 9, 9, 9, 9, 9, 9, 9,X_, // [16] <SCRI
X_, 2, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 18, 9, 9, 9, 9, 9, 9,X_, // [17] <SCRIP
X_,19, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 19,19, 9,X_, // [18] <SCRIPT
20,19,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,X_, // [19] <SCRIPT .*
19,19,19,19, 19,19,21,19, 19,19,19,19, 19,19,19,19, 19,19,19,X_, // [20] <SCRIPT .*<
19,19,19,19, 19,19,19,22, 19,19,19,19, 19,19,19,19, 21,21,19,X_, // [21] <SCRIPT .*</ allow SP CR LF
19,19,19,19, 19,19,19,19, 23,19,19,19, 19,19,19,19, 19,19,19,X_, // [22] <SCRIPT .*</S
19,19,19,19, 19,19,19,19, 19,24,19,19, 19,19,19,19, 19,19,19,X_, // [23] <SCRIPT .*</SC
19,19,19,19, 19,19,19,19, 19,19,25,19, 19,19,19,19, 19,19,19,X_, // [24] <SCRIPT .*</SCR
19,19,19,19, 19,19,19,19, 19,19,19,26, 19,19,19,19, 19,19,19,X_, // [25] <SCRIPT .*</SCRI
19,19,19,19, 19,19,19,19, 19,19,19,19, 27,19,19,19, 19,19,19,X_, // [26] <SCRIPT .*</SCRIP
19, 2,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,X_, // [27] <SCRIPT .*</SCRIPT
// < > ! - " ' / S C R I P T Y L E CR NL PL xx
X_, 2, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 9,29, 9, 9, 9, 9, 9,X_, // [28] <ST
X_, 2, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 9, 9,30, 9, 9, 9, 9,X_, // [29] <STY
X_, 2, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 9, 9, 9,31, 9, 9, 9,X_, // [30] <STYL
X_,32, 9, 9, 10,11, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 32,32, 9,X_, // [31] <STYLE
33,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,X_, // [32] <STYLE .*
32,32,32,32, 32,32,34,32, 32,32,32,32, 32,32,32,32, 32,32,32,X_, // [33] <STYLE .*<
32,32,32,32, 32,32,32,35, 32,32,32,32, 32,32,32,32, 34,34,32,X_, // [34] <STYLE .*</ allow SP CR LF
32,32,32,32, 32,32,32,32, 32,32,32,32, 36,32,32,32, 32,32,32,X_, // [35] <STYLE .*</S
32,32,32,32, 32,32,32,32, 32,32,32,32, 32,37,32,32, 32,32,32,X_, // [36] <STYLE .*</ST
32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,38,32, 32,32,32,X_, // [37] <STYLE .*</STY
32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,39, 32,32,32,X_, // [38] <STYLE .*</STYL
32, 2,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,X_, // [39] <STYLE .*</STYLE
};
#undef OK
#undef X_
enum
{
UTFmax = 4, // maximum bytes per rune
Runesync = 0x80, // cannot represent part of a UTF sequence (<)
Runeself = 0x80, // rune and UTF sequences are the same (<)
Runeerror = 0xFFFD, // decoding error in UTF
Runemax = 0x10FFFF, // maximum rune value
};
// Debugging. Not thread safe.
static char gDisplayPiece[32];
const uint8 gCharlen[16] = {1,1,1,1, 1,1,1,1, 1,1,1,1, 2,2,3,4};
char* DisplayPiece(const char* next_byte_, int byte_length_) {
// Copy up to 8 UTF-8 chars to buffer
int k = 0; // byte count
int n = 0; // character count
for (int i = 0; i < byte_length_; ++i) {
char c = next_byte_[i];
if ((c & 0xc0) != 0x80) {
// Beginning of a UTF-8 character
int charlen = gCharlen[static_cast<uint8>(c) >> 4];
if (i + charlen > byte_length_) {break;} // Not enough room for full char
if (k >= (32 - 7)) {break;} // Not necessarily enough room
if (n >= 8) {break;} // Enough characters already
++n;
}
if (c == '<') {
memcpy(&gDisplayPiece[k], "&lt;", 4); k += 4;
} else if (c == '>') {
memcpy(&gDisplayPiece[k], "&gt;", 4); k += 4;
} else if (c == '&') {
memcpy(&gDisplayPiece[k], "&amp;", 5); k += 5;
} else if (c == '\'') {
memcpy(&gDisplayPiece[k], "&apos;", 6); k += 6;
} else if (c == '"') {
memcpy(&gDisplayPiece[k], "&quot;", 6); k += 6;
} else {
gDisplayPiece[k++] = c;
}
}
gDisplayPiece[k++] = '\0';
return gDisplayPiece;
}
// runetochar copies (encodes) one rune, pointed to by r, to at most
// UTFmax bytes starting at s and returns the number of bytes generated.
int runetochar(char *str, const char32 *rune) {
// Convert to unsigned for range check.
unsigned long c;
// 1 char 00-7F
c = *rune;
if(c <= 0x7F) {
str[0] = c;
return 1;
}
// 2 char 0080-07FF
if(c <= 0x07FF) {
str[0] = 0xC0 | (c >> 1*6);
str[1] = 0x80 | (c & 0x3F);
return 2;
}
// Range check
if (c > Runemax) {
c = Runeerror;
}
// 3 char 0800-FFFF
if (c <= 0xFFFF) {
str[0] = 0xE0 | (c >> 2*6);
str[1] = 0x80 | ((c >> 1*6) & 0x3F);
str[2] = 0x80 | (c & 0x3F);
return 3;
}
// 4 char 10000-1FFFFF
str[0] = 0xF0 | (c >> 3*6);
str[1] = 0x80 | ((c >> 2*6) & 0x3F);
str[2] = 0x80 | ((c >> 1*6) & 0x3F);
str[3] = 0x80 | (c & 0x3F);
return 4;
}
// Convert GetTimeOfDay output to 64-bit usec
static inline uint64 Microseconds(const struct timeval& t) {
// The SumReducer uses uint64, so convert to (uint64) microseconds,
// not (double) seconds.
return t.tv_sec * 1000000ULL + t.tv_usec;
}
// Useful for converting an entity to an ascii value.
// RETURNS unicode value, or -1 if entity isn't valid. Don't include & or ;
int LookupEntity(const char* entity_name, int entity_len) {
// Make a C string
if (entity_len >= 16) {return -1;} // All real entities are shorter
char temp[16];
memcpy(temp, entity_name, entity_len);
temp[entity_len] = '\0';
int match = BinarySearch(temp, 0, kNameToEntitySize, kNameToEntity);
if (match >= 0) {return kNameToEntity[match].i;}
return -1;
}
bool ascii_isdigit(char c) {
return ('0' <= c) && (c <= '9');
}
bool ascii_isxdigit(char c) {
if (('0' <= c) && (c <= '9')) {return true;}
if (('a' <= c) && (c <= 'f')) {return true;}
if (('A' <= c) && (c <= 'F')) {return true;}
return false;
}
bool ascii_isalnum(char c) {
if (('0' <= c) && (c <= '9')) {return true;}
if (('a' <= c) && (c <= 'z')) {return true;}
if (('A' <= c) && (c <= 'Z')) {return true;}
return false;
}
int hex_digit_to_int(char c) {
if (('0' <= c) && (c <= '9')) {return c - '0';}
if (('a' <= c) && (c <= 'f')) {return c - 'a' + 10;}
if (('A' <= c) && (c <= 'F')) {return c - 'A' + 10;}
return 0;
}
static int32 strto32_base10(const char* nptr, const char* limit,
const char **endptr) {
*endptr = nptr;
while (nptr < limit && *nptr == '0') {
++nptr;
}
if (nptr == limit || !ascii_isdigit(*nptr))
return -1;
const char* end_digits_run = nptr;
while (end_digits_run < limit && ascii_isdigit(*end_digits_run)) {
++end_digits_run;
}
*endptr = end_digits_run;
const int num_digits = end_digits_run - nptr;
// kint32max == 2147483647.
if (num_digits < 9 ||
(num_digits == 10 && memcmp(nptr, "2147483647", 10) <= 0)) {
int value = 0;
for (; nptr < end_digits_run; ++nptr) {
value *= 10;
value += *nptr - '0';
}
// Overflow past the last valid unicode codepoint
// (0x10ffff) is converted to U+FFFD by FixUnicodeValue().
return FixUnicodeValue(value);
} else {
// Overflow: can't fit in an int32;
// returns the replacement character 0xFFFD.
return 0xFFFD;
}
}
static int32 strto32_base16(const char* nptr, const char* limit,
const char **endptr) {
*endptr = nptr;
while (nptr < limit && *nptr == '0') {
++nptr;
}
if (nptr == limit || !ascii_isxdigit(*nptr)) {
return -1;
}
const char* end_xdigits_run = nptr;
while (end_xdigits_run < limit && ascii_isxdigit(*end_xdigits_run)) {
++end_xdigits_run;
}
*endptr = end_xdigits_run;
const int num_xdigits = end_xdigits_run - nptr;
// kint32max == 0x7FFFFFFF.
if (num_xdigits < 8 || (num_xdigits == 8 && nptr[0] < '8')) {
int value = 0;
for (; nptr < end_xdigits_run; ++nptr) {
value <<= 4;
value += hex_digit_to_int(*nptr);
}
// Overflow past the last valid unicode codepoint
// (0x10ffff) is converted to U+FFFD by FixUnicodeValue().
return FixUnicodeValue(value);
} else {
// Overflow: can't fit in an int32;
// returns the replacement character 0xFFFD.
return 0xFFFD;
}
}
// Unescape the current character pointed to by src. SETS the number
// of chars read for the conversion (in UTF8). If src isn't a valid entity,
// just consume the & and RETURN -1. If src doesn't point to & -- which it
// should -- set src_consumed to 0 and RETURN -1.
int ReadEntity(const char* src, int srcn, int* src_consumed) {
const char* const srcend = src + srcn;
if (srcn == 0 || *src != '&') { // input should start with an ampersand
*src_consumed = 0;
return -1;
}
*src_consumed = 1; // we'll get the & at least
// The standards are a bit unclear on when an entity ends. Certainly a ";"
// ends one, but spaces probably do too. We follow the lead of both IE and
// Netscape, which as far as we can tell end numeric entities (1st case below)
// at any non-digit, and end character entities (2nd case) at any non-alnum.
const char* entstart, *entend; // where the entity starts and ends
entstart = src + 1; // read past the &
int entval; // UCS2 value of the entity
if ( *entstart == '#' ) { // -- 1st case: numeric entity
if ( entstart + 2 >= srcend ) {
return -1; // no way a legitimate number could fit
} else if ( entstart[1] == 'x' || entstart[1] == 'X' ) { // hex numeric
entval = strto32_base16(entstart + 2, srcend, &entend);
} else { // decimal numeric entity
entval = strto32_base10(entstart+1, srcend, &entend);
}
if (entval == -1 || entend > srcend) {
return -1; // not entirely correct, but close enough
}
} else { // -- 2nd case: character entity
for (entend = entstart;
entend < srcend && ascii_isalnum(*entend);
++entend ) {
// entity consists of alphanumeric chars
}
entval = LookupEntity(entstart, entend - entstart);
if (entval < 0) {
return -1; // not a legal entity name
}
// Now we do a strange-seeming IE6-compatibility check: if entval is
// >= 256, it *must* be followed by a semicolon or it's not considered
// an entity. The problem is lots of the newfangled entity names, like
// "lang", also occur in URL CGI arguments: "/search?q=test&lang=en".
// When these links are written in HTML, it would be really bad if the
// "&lang" were treated as an entity, which is what the spec says
// *should* happen (even when the HTML is inside an "A HREF" tag!)
// IE ignores the spec for these new, high-value entities, so we do too.
if ( entval >= 256 && !(entend < srcend && *entend == ';') ) {
return -1; // make non-;-terminated entity illegal
}
}
// Finally, figure out how much src was consumed
if ( entend < srcend && *entend == ';' ) {
entend++; // standard says ; terminator is special
}
*src_consumed = entend - src;
return entval;
}
// Src points to '&'
// Writes entity value to dst. Returns take(src), put(dst) byte counts
void EntityToBuffer(const char* src, int len, char* dst,
int* tlen, int* plen) {
char32 entval = ReadEntity(src, len, tlen);
// ReadEntity does this already: entval = FixUnicodeValue(entval);
// Convert UTF-32 to UTF-8
if (entval > 0) {
*plen = runetochar(dst, &entval);
} else {
// Illegal entity; ignore the '&'
*tlen = 1;
*plen = 0;
}
}
// Returns true if character is < > or &, none of which are letters
bool inline IsSpecial(char c) {
if ((c & 0xe0) == 0x20) {
return kSpecialSymbol[static_cast<uint8>(c)];
}
return false;
}
// Quick Skip to next letter or < > & or to end of string (eos)
// Always return is_letter for eos
int ScanToLetterOrSpecial(const char* src, int len) {
int bytes_consumed;
StringPiece str(src, len);
UTF8GenericScan(&utf8scannot_lettermarkspecial_obj, str, &bytes_consumed);
return bytes_consumed;
}
// src points to non-letter, such as tag-opening '<'
// Return length from here to next possible letter
// On eos or another < before >, return 1
// advances <tag>
// | |
// advances <tag> ... </tag> for <script> <style>
// | |
// advances <!-- ... <tag> ... -->
// | |
// advances <tag
// || (1)
// advances <tag <tag2>
// || (1)
int ScanToPossibleLetter(const char* isrc, int len, int max_exit_state) {
const uint8* src = reinterpret_cast<const uint8*>(isrc);
const uint8* srclimit = src + len;
const uint8* tagParseTbl = kTagParseTbl_0;
int e = 0;
while (src < srclimit) {
e = tagParseTbl[kCharToSub[*src++]];
if (e <= max_exit_state) {
// We overshot by one byte
--src;
break;
}
tagParseTbl = &kTagParseTbl_0[e * 20];
}
if (src >= srclimit) {
// We fell off the end of the text.
// It looks like the most common case for this is a truncated file, not
// mismatched angle brackets. So we pretend that the last char was '>'
return len;
}
// OK to be in state 0 or state 2 at exit
if ((e != 0) && (e != 2)) {
// Error, '<' followed by '<'
// We want to back up to first <, then advance by one byte past it
int offset = src - reinterpret_cast<const uint8*>(isrc);
// Backscan to first '<' and return enough length to just get past it
--offset; // back up over the second '<', which caused us to stop
while ((0 < offset) && (isrc[offset] != '<')) {
// Find the first '<', which is unmatched
--offset;
}
// skip to just beyond first '<'
return offset + 1;
}
return src - reinterpret_cast<const uint8*>(isrc);
}
ScriptScanner::ScriptScanner(const char* buffer,
int buffer_length,
bool is_plain_text)
: start_byte_(buffer),
next_byte_(buffer),
next_byte_limit_(buffer + buffer_length),
byte_length_(buffer_length),
is_plain_text_(is_plain_text),
letters_marks_only_(true),
one_script_only_(true),
exit_state_(kMaxExitStateLettersMarksOnly) {
script_buffer_ = new char[kMaxScriptBuffer];
script_buffer_lower_ = new char[kMaxScriptLowerBuffer];
map2original_.Clear(); // map from script_buffer_ to buffer
map2uplow_.Clear(); // map from script_buffer_lower_ to script_buffer_
}
// Extended version to allow spans of any non-tag text and spans of mixed script
ScriptScanner::ScriptScanner(const char* buffer,
int buffer_length,
bool is_plain_text,
bool any_text,
bool any_script)
: start_byte_(buffer),
next_byte_(buffer),
next_byte_limit_(buffer + buffer_length),
byte_length_(buffer_length),
is_plain_text_(is_plain_text),
letters_marks_only_(!any_text),
one_script_only_(!any_script),
exit_state_(any_text ? kMaxExitStateAllText : kMaxExitStateLettersMarksOnly) {
script_buffer_ = new char[kMaxScriptBuffer];
script_buffer_lower_ = new char[kMaxScriptLowerBuffer];
map2original_.Clear(); // map from script_buffer_ to buffer
map2uplow_.Clear(); // map from script_buffer_lower_ to script_buffer_
}
ScriptScanner::~ScriptScanner() {
delete[] script_buffer_;
delete[] script_buffer_lower_;
}
// Get to the first real non-tag letter or entity that is a letter
// Sets script of that letter
// Return len if no more letters
int ScriptScanner::SkipToFrontOfSpan(const char* src, int len, int* script) {
int sc = UNKNOWN_ULSCRIPT;
int skip = 0;
int tlen, plen;
// Do run of non-letters (tag | &NL | NL)*
tlen = 0;
while (skip < len) {
// Do fast scan to next interesting byte
// int oldskip = skip;
skip += ScanToLetterOrSpecial(src + skip, len - skip);
// Check for no more letters/specials
if (skip >= len) {
// All done
*script = sc;
return len;
}
// We are at a letter, nonletter, tag, or entity
if (IsSpecial(src[skip]) && !is_plain_text_) {
if (src[skip] == '<') {
// Begining of tag; skip to end and go around again
tlen = ScanToPossibleLetter(src + skip, len - skip,
exit_state_);
sc = 0;
} else if (src[skip] == '>') {
// Unexpected end of tag; skip it and go around again
tlen = 1; // Over the >
sc = 0;
} else if (src[skip] == '&') {
// Expand entity, no advance
char temp[4];
EntityToBuffer(src + skip, len - skip,
temp, &tlen, &plen);
sc = GetUTF8LetterScriptNum(temp);
}
} else {
// Update 1..4 bytes
tlen = UTF8OneCharLen(src + skip);
sc = GetUTF8LetterScriptNum(src + skip);
}
if (sc != 0) {break;} // Letter found
skip += tlen; // Else advance
}
*script = sc;
return skip;
}
// These are for ASCII-only tag names
// Compare one letter uplow to c, ignoring case of uplowp
inline bool EqCase(char uplow, char c) {
return (uplow | 0x20) == c;
}
// These are for ASCII-only tag names
// Return true for space / < > etc. all less than 0x40
inline bool NeqLetter(char c) {
return c < 0x40;
}
// These are for ASCII-only tag names
// Return true for space \n false for \r
inline bool WS(char c) {
return (c == ' ') || (c == '\n');
}
// Canonical CR or LF
static const char LF = '\n';
// The naive loop scans from next_byte_ to script_buffer_ until full.
// But this can leave an awkward hard-to-identify short fragment at the
// end of the input. We would prefer to make the next-to-last fragment
// shorter and the last fragment longer.
// Copy next run of non-tag characters to buffer [NUL terminated]
// This just replaces tags with space or \n and removes entities.
// Tags <br> <p> and <tr> are replaced with \n. Non-letter sequences
// including \r or \n are replaced by \n. All other tags and skipped text
// are replaced with ASCII space.
//
// Buffer ALWAYS has leading space and trailing space space space NUL
bool ScriptScanner::GetOneTextSpan(LangSpan* span) {
span->text = script_buffer_;
span->text_bytes = 0;
span->offset = next_byte_ - start_byte_;
span->ulscript = UNKNOWN_ULSCRIPT;
span->lang = UNKNOWN_LANGUAGE;
span->truncated = false;
int put_soft_limit = kMaxScriptBytes - kWithinScriptTail;
if ((kMaxScriptBytes <= byte_length_) &&
(byte_length_ < (2 * kMaxScriptBytes))) {
// Try to split the last two fragments in half
put_soft_limit = byte_length_ / 2;
}
script_buffer_[0] = ' '; // Always a space at front of output
script_buffer_[1] = '\0';
int take = 0;
int put = 1; // Start after the initial space
int tlen, plen;
if (byte_length_ <= 0) {
return false; // No more text to be found
}
// Go over alternating spans of text and tags,
// copying letters to buffer with single spaces for each run of non-letters
bool last_byte_was_space = false;
while (take < byte_length_) {
char c = next_byte_[take];
if (c == '\r') {c = LF;} // Canonical CR or LF
if (c == '\n') {c = LF;} // Canonical CR or LF
if (IsSpecial(c) && !is_plain_text_) {
if (c == '<') {
// Replace tag with space
c = ' '; // for almost-full test below
// or if <p> <br> <tr>, replace with \n
if (take < (byte_length_ - 3)) {
if (EqCase(next_byte_[take + 1], 'p') &&
NeqLetter(next_byte_[take + 2])) {
c = LF;
}
if (EqCase(next_byte_[take + 1], 'b') &&
EqCase(next_byte_[take + 2], 'r') &&
NeqLetter(next_byte_[take + 3])) {
c = LF;
}
if (EqCase(next_byte_[take + 1], 't') &&
EqCase(next_byte_[take + 2], 'r') &&
NeqLetter(next_byte_[take + 3])) {
c = LF;
}
}
// Begining of tag; skip to end and go around again
tlen = 1 + ScanToPossibleLetter(next_byte_ + take, byte_length_ - take,
exit_state_);
// Copy one byte, compressing spaces
if (!last_byte_was_space || !WS(c)) {
script_buffer_[put++] = c; // Advance dest
last_byte_was_space = WS(c);
}
} else if (c == '>') {
// Unexpected end of tag; copy it and go around again
tlen = 1; // Over the >
script_buffer_[put++] = c; // Advance dest
} else if (c == '&') {
// Expand entity, no advance
EntityToBuffer(next_byte_ + take, byte_length_ - take,
script_buffer_ + put, &tlen, &plen);
put += plen; // Advance dest
}
take += tlen; // Advance source
} else {
// Copy one byte, compressing spaces
if (!last_byte_was_space || !WS(c)) {
script_buffer_[put++] = c; // Advance dest
last_byte_was_space = WS(c);
}
++take; // Advance source
}
if (WS(c) &&
(put >= put_soft_limit)) {
// Buffer is almost full
span->truncated = true;
break;
}
if (put >= kMaxScriptBytes) {
// Buffer is completely full
span->truncated = true;
break;
}
}
// Almost done. Back up to a character boundary if needed
while ((0 < take) && ((next_byte_[take] & 0xc0) == 0x80)) {
// Back up over continuation byte
--take;
--put;
}
// Update input position
next_byte_ += take;
byte_length_ -= take;
// Put four more spaces/NUL. Worst case is abcd _ _ _ \0
// kMaxScriptBytes | | put
script_buffer_[put + 0] = ' ';
script_buffer_[put + 1] = ' ';
script_buffer_[put + 2] = ' ';
script_buffer_[put + 3] = '\0';
span->text_bytes = put; // Does not include the last four chars above
return true;
}
// Copy next run of same-script non-tag letters to buffer [NUL terminated]
// Buffer ALWAYS has leading space and trailing space space space NUL
bool ScriptScanner::GetOneScriptSpan(LangSpan* span) {
if (!letters_marks_only_) {
// Return non-tag text, including punctuation and digits
return GetOneTextSpan(span);
}
span->text = script_buffer_;
span->text_bytes = 0;
span->offset = next_byte_ - start_byte_;
span->ulscript = UNKNOWN_ULSCRIPT;
span->lang = UNKNOWN_LANGUAGE;
span->truncated = false;
// struct timeval script_start, script_mid, script_end;
int put_soft_limit = kMaxScriptBytes - kWithinScriptTail;
if ((kMaxScriptBytes <= byte_length_) &&
(byte_length_ < (2 * kMaxScriptBytes))) {
// Try to split the last two fragments in half
put_soft_limit = byte_length_ / 2;
}
int spanscript; // The script of this span
int sc = UNKNOWN_ULSCRIPT; // The script of next character
int tlen = 0;
int plen = 0;
script_buffer_[0] = ' '; // Always a space at front of output
script_buffer_[1] = '\0';
int take = 0;
int put = 1; // Start after the initial space
// Build offsets from span->text back to start_byte_ + span->offset
// This mapping reflects deletion of non-letters, expansion of
// entities, etc.
map2original_.Clear();
map2original_.Delete(span->offset); // So that MapBack(0) gives offset
// gettimeofday(&script_start, NULL);
// Get to the first real non-tag letter or entity that is a letter
int skip = SkipToFrontOfSpan(next_byte_, byte_length_, &spanscript);
next_byte_ += skip;
byte_length_ -= skip;
if (skip != 1) {
map2original_.Delete(skip);
map2original_.Insert(1);
} else {
map2original_.Copy(1);
}
if (byte_length_ <= 0) {
map2original_.Reset();
return false; // No more letters to be found
}
// gettimeofday(&script_mid, NULL);
// There is at least one letter, so we know the script for this span
span->ulscript = (ULScript)spanscript;
// Go over alternating spans of same-script letters and non-letters,
// copying letters to buffer with single spaces for each run of non-letters
while (take < byte_length_) {
// Copy run of letters in same script (&LS | LS)*
int letter_count = 0; // Keep track of word length
bool need_break = false;
while (take < byte_length_) {
// We are at a letter, nonletter, tag, or entity
if (IsSpecial(next_byte_[take]) && !is_plain_text_) {
if (next_byte_[take] == '<') {
// Begining of tag
sc = 0;
break;
} else if (next_byte_[take] == '>') {
// Unexpected end of tag
sc = 0;
break;
} else if (next_byte_[take] == '&') {
// Copy entity, no advance
EntityToBuffer(next_byte_ + take, byte_length_ - take,
script_buffer_ + put, &tlen, &plen);
sc = GetUTF8LetterScriptNum(script_buffer_ + put);
}
} else {
// Real letter, safely copy up to 4 bytes, increment by 1..4
// Will update by 1..4 bytes at Advance, below
tlen = plen = UTF8OneCharLen(next_byte_ + take);
if (take < (byte_length_ - 3)) {
// X86 fast case, does unaligned load/store
UNALIGNED_STORE32(script_buffer_ + put,
UNALIGNED_LOAD32(next_byte_ + take));
} else {
// Slow case, happens 1-3 times per input document
memcpy(script_buffer_ + put, next_byte_ + take, plen);
}
sc = GetUTF8LetterScriptNum(next_byte_ + take);
}
// Allow continue across a single letter in a different script:
// A B D = three scripts, c = common script, i = inherited script,
// - = don't care, ( = take position before the += below
// AAA(A- continue
//
// AAA(BA continue
// AAA(BB break
// AAA(Bc continue (breaks after B)
// AAA(BD break
// AAA(Bi break
//
// AAA(c- break
//
// AAA(i- continue
//
if ((sc != spanscript) && (sc != ULScript_Inherited)) {
// Might need to break this script span
if (sc == ULScript_Common) {
need_break = true;
} else {
// Look at next following character, ignoring entity as Common
int sc2 = GetUTF8LetterScriptNum(next_byte_ + take + tlen);
if ((sc2 != ULScript_Common) && (sc2 != spanscript)) {
// We found a non-trivial change of script
if (one_script_only_) {
need_break = true;
}
}
}
}
if (need_break) {break;} // Non-letter or letter in wrong script
take += tlen; // Advance
put += plen; // Advance
// Update the offset map to reflect take/put lengths
if (tlen == plen) {
map2original_.Copy(tlen);
} else if (tlen < plen) {
map2original_.Copy(tlen);
map2original_.Insert(plen - tlen);
} else { // plen < tlen
map2original_.Copy(plen);
map2original_.Delete(tlen - plen);
}
++letter_count;
if (put >= kMaxScriptBytes) {
// Buffer is full
span->truncated = true;
break;
}
} // End while letters
// Do run of non-letters (tag | &NL | NL)*
while (take < byte_length_) {
// Do fast scan to next interesting byte
tlen = ScanToLetterOrSpecial(next_byte_ + take, byte_length_ - take);
take += tlen;
map2original_.Delete(tlen);
if (take >= byte_length_) {break;} // Might have scanned to end
// We are at a letter, nonletter, tag, or entity
if (IsSpecial(next_byte_[take]) && !is_plain_text_) {
if (next_byte_[take] == '<') {
// Begining of tag; skip to end and go around again
tlen = ScanToPossibleLetter(next_byte_ + take, byte_length_ - take,
exit_state_);
sc = 0;
} else if (next_byte_[take] == '>') {
// Unexpected end of tag; skip it and go around again
tlen = 1; // Over the >
sc = 0;
} else if (next_byte_[take] == '&') {
// Expand entity, no advance
EntityToBuffer(next_byte_ + take, byte_length_ - take,
script_buffer_ + put, &tlen, &plen);
sc = GetUTF8LetterScriptNum(script_buffer_ + put);
}
} else {
// Update 1..4
tlen = UTF8OneCharLen(next_byte_ + take);
sc = GetUTF8LetterScriptNum(next_byte_ + take);
}
if (sc != 0) {break;} // Letter found
take += tlen; // Else advance
map2original_.Delete(tlen);
} // End while not-letters
script_buffer_[put++] = ' ';
map2original_.Insert(1);
// Letter in wrong script ?
if ((sc != spanscript) && (sc != ULScript_Inherited)) {break;}
if (put >= put_soft_limit) {
// Buffer is almost full
span->truncated = true;
break;
}
}
// Almost done. Back up to a character boundary if needed
while ((0 < take) && (take < byte_length_) &&
((next_byte_[take] & 0xc0) == 0x80)) {
// Back up over continuation byte
--take;
--put;
}
// Update input position
next_byte_ += take;
byte_length_ -= take;
// Put four more spaces/NUL. Worst case is abcd _ _ _ \0
// kMaxScriptBytes | | put
script_buffer_[put + 0] = ' ';
script_buffer_[put + 1] = ' ';
script_buffer_[put + 2] = ' ';
script_buffer_[put + 3] = '\0';
map2original_.Insert(4);
map2original_.Reset();
span->text_bytes = put; // Does not include the last four chars above
return true;
}
// Force Latin, Cyrillic, Armenian, Greek scripts to be lowercase
// List changes with each version of Unicode, so always lowercase
// Unicode 6.2.0:
// ARMENIAN COPTIC CYRILLIC DESERET GEORGIAN GLAGOLITIC GREEK LATIN
void ScriptScanner::LowerScriptSpan(LangSpan* span) {
// If needed, lowercase all the text. If we do it sooner, might miss
// lowercasing an entity such as &Aacute;
// We only need to do this for Latn and Cyrl scripts
map2uplow_.Clear();
if (true ||
(span->ulscript == ULScript_Latin) ||
(span->ulscript == ULScript_Cyrillic) ||
(span->ulscript == ULScript_Armenian) ||
(span->ulscript == ULScript_Greek)) {
// Full Unicode lowercase of the entire buffer, including
// four pad bytes off the end.
// Ahhh. But the last byte 0x00 is not interchange-valid, so we do 3 pad
// bytes and put the 0x00 in explicitly.
// Build an offset map from script_buffer_lower_ back to script_buffer_
int consumed, filled, changed;
StringPiece istr(span->text, span->text_bytes + 3);
StringPiece ostr(script_buffer_lower_, kMaxScriptLowerBuffer);
UTF8GenericReplace(&utf8repl_lettermarklower_obj,
istr, ostr, is_plain_text_,
&consumed, &filled, &changed, &map2uplow_);
script_buffer_lower_[filled] = '\0';
span->text = script_buffer_lower_;
span->text_bytes = filled - 3;
} else {
map2uplow_.Copy(span->text_bytes + 3);
}
map2uplow_.Reset();
}
// Copy next run of same-script non-tag letters to buffer [NUL terminated]
// Force Latin, Cyrillic, Greek scripts to be lowercase
// Buffer ALWAYS has leading space and trailing space space space NUL
bool ScriptScanner::GetOneScriptSpanLower(LangSpan* span) {
bool ok = GetOneScriptSpan(span);
LowerScriptSpan(span);
return ok;
}
// Maps byte offset in most recent GetOneScriptSpan/Lower
// span->text [0..text_bytes] into an additional byte offset from
// span->offset, to get back to corresponding text in the original
// input buffer.
// text_offset must be the first byte
// of a UTF-8 character, or just beyond the last character. Normally this
// routine is called with the first byte of an interesting range and
// again with the first byte of the following range.
int ScriptScanner::MapBack(int text_offset) {
return map2original_.MapBack(map2uplow_.MapBack(text_offset));
}
// Gets lscript number for letters; always returns
// 0 (common script) for non-letters
int GetUTF8LetterScriptNum(const char* src) {
int srclen = UTF8OneCharLen(src);
const uint8* usrc = reinterpret_cast<const uint8*>(src);
return UTF8GenericPropertyTwoByte(&utf8prop_lettermarkscriptnum_obj,
&usrc, &srclen);
}
} // namespace CLD2
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