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-rw-r--r--browser/components/translation/cld2/internal/utf8statetable.cc1369
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diff --git a/browser/components/translation/cld2/internal/utf8statetable.cc b/browser/components/translation/cld2/internal/utf8statetable.cc
deleted file mode 100644
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--- a/browser/components/translation/cld2/internal/utf8statetable.cc
+++ /dev/null
@@ -1,1369 +0,0 @@
-// 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.
-
-//
-// State Table follower for scanning UTF-8 strings without converting to
-// 32- or 16-bit Unicode values.
-//
-
-#ifdef COMPILER_MSVC
-// MSVC warns: warning C4309: 'initializing' : truncation of constant value
-// But the value is in fact not truncated. 0xFF still comes out 0xFF at
-// runtime.
-#pragma warning ( disable : 4309 )
-#endif
-
-#include "utf8statetable.h"
-
-#include <stdint.h> // for uintptr_t
-#include <string.h> // for NULL, memcpy, memmove
-
-#include "integral_types.h" // for uint8, uint32, int8
-#include "stringpiece.h"
-#include "offsetmap.h"
-
-
-namespace CLD2 {
-
-static const int kReplaceAndResumeFlag = 0x80; // Bit in del byte to distinguish
- // optional next-state field
- // after replacement text
-static const int kHtmlPlaintextFlag = 0x80; // Bit in add byte to distinguish
- // HTML replacement vs. plaintext
-
-
-/**
- * This code implements a little interpreter for UTF8 state
- * tables. There are three kinds of quite-similar state tables,
- * property, scanning, and replacement. Each state in one of
- * these tables consists of an array of 256 or 64 one-byte
- * entries. The state is subscripted by an incoming source byte,
- * and the entry either specifies the next state or specifies an
- * action. Space-optimized tables have full 256-entry states for
- * the first byte of a UTF-8 character, but only 64-entry states
- * for continuation bytes. Space-optimized tables may only be
- * used with source input that has been checked to be
- * structurally- (or stronger interchange-) valid.
- *
- * A property state table has an unsigned one-byte property for
- * each possible UTF-8 character. One-byte character properties
- * are in the state[0] array, while for other lengths the
- * state[0] array gives the next state, which contains the
- * property value for two-byte characters or yet another state
- * for longer ones. The code simply loads the right number of
- * next-state values, then returns the final byte as property
- * value. There are no actions specified in property tables.
- * States are typically shared for multi-byte UTF-8 characters
- * that all have the same property value.
- *
- * A scanning state table has entries that are either a
- * next-state specifier for bytes that are accepted by the
- * scanner, or an exit action for the last byte of each
- * character that is rejected by the scanner.
- *
- * Scanning long strings involves a tight loop that picks up one
- * byte at a time and follows next-state value back to state[0]
- * for each accepted UTF-8 character. Scanning stops at the end
- * of the string or at the first character encountered that has
- * an exit action such as "reject". Timing information is given
- * below.
- *
- * Since so much of Google's text is 7-bit-ASCII values
- * (approximately 94% of the bytes of web documents), the
- * scanning interpreter has two speed optimizations. One checks
- * 8 bytes at a time to see if they are all in the range lo..hi,
- * as specified in constants in the overall statetable object.
- * The check involves ORing together four 4-byte values that
- * overflow into the high bit of some byte when a byte is out of
- * range. For seven-bit-ASCII, lo is 0x20 and hi is 0x7E. This
- * loop is about 8x faster than the one-byte-at-a-time loop.
- *
- * If checking for exit bytes in the 0x00-0x1F and 7F range is
- * unneeded, an even faster loop just looks at the high bits of
- * 8 bytes at once, and is about 1.33x faster than the lo..hi
- * loop.
- *
- * Exit from the scanning routines backs up to the first byte of
- * the rejected character, so the text spanned is always a
- * complete number of UTF-8 characters. The normal scanning exit
- * is at the first rejected character, or at the end of the
- * input text. Scanning also exits on any detected ill-formed
- * character or at a special do-again action built into some
- * exit-optimized tables. The do-again action gets back to the
- * top of the scanning loop to retry eight-byte ASCII scans. It
- * is typically put into state tables after four seven-bit-ASCII
- * characters in a row are seen, to allow restarting the fast
- * scan after some slower processing of multi-byte characters.
- *
- * A replacement state table is similar to a scanning state
- * table but has more extensive actions. The default
- * byte-at-a-time loop copies one byte from source to
- * destination and goes to the next state. The replacement
- * actions overwrite 1-3 bytes of the destination with different
- * bytes, possibly shortening the output by 1 or 2 bytes. The
- * replacement bytes come from within the state table, from
- * dummy states inserted just after any state that contains a
- * replacement action. This gives a quick address calculation for
- * the replacement byte(s) and gives some cache locality.
- *
- * Additional replacement actions use one or two bytes from
- * within dummy states to index a side table of more-extensive
- * replacements. The side table specifies a length of 0..15
- * destination bytes to overwrite and a length of 0..127 bytes
- * to overwrite them with, plus the actual replacement bytes.
- *
- * This side table uses one extra bit to specify a pair of
- * replacements, the first to be used in an HTML context and the
- * second to be used in a plaintext context. This allows
- * replacements that are spelled with "&lt;" in the former
- * context and "<" in the latter.
- *
- * The side table also uses an extra bit to specify a non-zero
- * next state after a replacement. This allows a combination
- * replacement and state change, used to implement a limited
- * version of the Boyer-Moore algorithm for multi-character
- * replacement without backtracking. This is useful when there
- * are overlapping replacements, such as ch => x and also c =>
- * y, the latter to be used only if the character after c is not
- * h. in this case, the state[0] table's entry for c would
- * change c to y and also have a next-state of say n, and the
- * state[n] entry for h would specify a replacement of the two
- * bytes yh by x. No backtracking is needed.
- *
- * A replacement table may also include the exit actions of a
- * scanning state table, so some character sequences can
- * terminate early.
- *
- * During replacement, an optional data structure called an
- * offset map can be updated to reflect each change in length
- * between source and destination. This offset map can later be
- * used to map destination-string offsets to corresponding
- * source-string offsets or vice versa.
- *
- * The routines below also have variants in which state-table
- * entries are all two bytes instead of one byte. This allows
- * tables with more than 240 total states, but takes up twice as
- * much space per state.
- *
-**/
-
-// Return true if current Tbl pointer is within state0 range
-// Note that unsigned compare checks both ends of range simultaneously
-static inline bool InStateZero(const UTF8ScanObj* st, const uint8* Tbl) {
- const uint8* Tbl0 = &st->state_table[st->state0];
- return (static_cast<uint32>(Tbl - Tbl0) < st->state0_size);
-}
-
-static inline bool InStateZero_2(const UTF8ReplaceObj_2* st,
- const unsigned short int* Tbl) {
- const unsigned short int* Tbl0 = &st->state_table[st->state0];
- // Word difference, not byte difference
- return (static_cast<uint32>(Tbl - Tbl0) < st->state0_size);
-}
-
-// UTF8PropObj, UTF8ScanObj, UTF8ReplaceObj are all typedefs of
-// UTF8MachineObj.
-
-static bool IsPropObj(const UTF8StateMachineObj& obj) {
- return obj.fast_state == NULL
- && obj.max_expand == 0;
-}
-
-static bool IsPropObj_2(const UTF8StateMachineObj_2& obj) {
- return obj.fast_state == NULL
- && obj.max_expand == 0;
-}
-
-static bool IsScanObj(const UTF8StateMachineObj& obj) {
- return obj.fast_state != NULL
- && obj.max_expand == 0;
-}
-
-static bool IsReplaceObj(const UTF8StateMachineObj& obj) {
- // Normally, obj.fast_state != NULL, but the handwritten tables
- // in utf8statetable_unittest don't handle fast_states.
- return obj.max_expand > 0;
-}
-
-static bool IsReplaceObj_2(const UTF8StateMachineObj_2& obj) {
- return obj.max_expand > 0;
-}
-
-// Look up property of one UTF-8 character and advance over it
-// Return 0 if input length is zero
-// Return 0 and advance one byte if input is ill-formed
-uint8 UTF8GenericProperty(const UTF8PropObj* st,
- const uint8** src,
- int* srclen) {
- if (*srclen <= 0) {
- return 0;
- }
-
- const uint8* lsrc = *src;
- const uint8* Tbl_0 = &st->state_table[st->state0];
- const uint8* Tbl = Tbl_0;
- int e;
- int eshift = st->entry_shift;
-
- // Short series of tests faster than switch, optimizes 7-bit ASCII
- unsigned char c = lsrc[0];
- if (static_cast<signed char>(c) >= 0) { // one byte
- e = Tbl[c];
- *src += 1;
- *srclen -= 1;
- } else if (((c & 0xe0) == 0xc0) && (*srclen >= 2)) { // two bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- *src += 2;
- *srclen -= 2;
- } else if (((c & 0xf0) == 0xe0) && (*srclen >= 3)) { // three bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- *src += 3;
- *srclen -= 3;
- }else if (((c & 0xf8) == 0xf0) && (*srclen >= 4)) { // four bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[3]];
- *src += 4;
- *srclen -= 4;
- } else { // Ill-formed
- e = 0;
- *src += 1;
- *srclen -= 1;
- }
- return e;
-}
-
-bool UTF8HasGenericProperty(const UTF8PropObj& st, const char* src) {
- const uint8* lsrc = reinterpret_cast<const uint8*>(src);
- const uint8* Tbl_0 = &st.state_table[st.state0];
- const uint8* Tbl = Tbl_0;
- int e;
- int eshift = st.entry_shift;
-
- // Short series of tests faster than switch, optimizes 7-bit ASCII
- unsigned char c = lsrc[0];
- if (static_cast<signed char>(c) >= 0) { // one byte
- e = Tbl[c];
- } else if ((c & 0xe0) == 0xc0) { // two bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- } else if ((c & 0xf0) == 0xe0) { // three bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- } else { // four bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[3]];
- }
- return e;
-}
-
-
-// BigOneByte versions are needed for tables > 240 states, but most
-// won't need the TwoByte versions.
-// Internally, to next-to-last offset is multiplied by 16 and the last
-// offset is relative instead of absolute.
-// Look up property of one UTF-8 character and advance over it
-// Return 0 if input length is zero
-// Return 0 and advance one byte if input is ill-formed
-uint8 UTF8GenericPropertyBigOneByte(const UTF8PropObj* st,
- const uint8** src,
- int* srclen) {
- if (*srclen <= 0) {
- return 0;
- }
-
- const uint8* lsrc = *src;
- const uint8* Tbl_0 = &st->state_table[st->state0];
- const uint8* Tbl = Tbl_0;
- int e;
- int eshift = st->entry_shift;
-
- // Short series of tests faster than switch, optimizes 7-bit ASCII
- unsigned char c = lsrc[0];
- if (static_cast<signed char>(c) >= 0) { // one byte
- e = Tbl[c];
- *src += 1;
- *srclen -= 1;
- } else if (((c & 0xe0) == 0xc0) && (*srclen >= 2)) { // two bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- *src += 2;
- *srclen -= 2;
- } else if (((c & 0xf0) == 0xe0) && (*srclen >= 3)) { // three bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << (eshift + 4)]; // 16x the range
- e = (reinterpret_cast<const int8*>(Tbl))[lsrc[1]];
- Tbl = &Tbl[e << eshift]; // Relative +/-
- e = Tbl[lsrc[2]];
- *src += 3;
- *srclen -= 3;
- }else if (((c & 0xf8) == 0xf0) && (*srclen >= 4)) { // four bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << (eshift + 4)]; // 16x the range
- e = (reinterpret_cast<const int8*>(Tbl))[lsrc[2]];
- Tbl = &Tbl[e << eshift]; // Relative +/-
- e = Tbl[lsrc[3]];
- *src += 4;
- *srclen -= 4;
- } else { // Ill-formed
- e = 0;
- *src += 1;
- *srclen -= 1;
- }
- return e;
-}
-
-// BigOneByte versions are needed for tables > 240 states, but most
-// won't need the TwoByte versions.
-bool UTF8HasGenericPropertyBigOneByte(const UTF8PropObj& st, const char* src) {
- const uint8* lsrc = reinterpret_cast<const uint8*>(src);
- const uint8* Tbl_0 = &st.state_table[st.state0];
- const uint8* Tbl = Tbl_0;
- int e;
- int eshift = st.entry_shift;
-
- // Short series of tests faster than switch, optimizes 7-bit ASCII
- unsigned char c = lsrc[0];
- if (static_cast<signed char>(c) >= 0) { // one byte
- e = Tbl[c];
- } else if ((c & 0xe0) == 0xc0) { // two bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- } else if ((c & 0xf0) == 0xe0) { // three bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << (eshift + 4)]; // 16x the range
- e = (reinterpret_cast<const int8*>(Tbl))[lsrc[1]];
- Tbl = &Tbl[e << eshift]; // Relative +/-
- e = Tbl[lsrc[2]];
- } else { // four bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << (eshift + 4)]; // 16x the range
- e = (reinterpret_cast<const int8*>(Tbl))[lsrc[2]];
- Tbl = &Tbl[e << eshift]; // Relative +/-
- e = Tbl[lsrc[3]];
- }
- return e;
-}
-
-
-// TwoByte versions are needed for tables > 240 states
-// Look up property of one UTF-8 character and advance over it
-// Return 0 if input length is zero
-// Return 0 and advance one byte if input is ill-formed
-uint8 UTF8GenericPropertyTwoByte(const UTF8PropObj_2* st,
- const uint8** src,
- int* srclen) {
- if (*srclen <= 0) {
- return 0;
- }
-
- const uint8* lsrc = *src;
- const unsigned short* Tbl_0 = &st->state_table[st->state0];
- const unsigned short* Tbl = Tbl_0;
- int e;
- int eshift = st->entry_shift;
-
- // Short series of tests faster than switch, optimizes 7-bit ASCII
- unsigned char c = lsrc[0];
- if (static_cast<signed char>(c) >= 0) { // one byte
- e = Tbl[c];
- *src += 1;
- *srclen -= 1;
- } else if (((c & 0xe0) == 0xc0) && (*srclen >= 2)) { // two bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- *src += 2;
- *srclen -= 2;
- } else if (((c & 0xf0) == 0xe0) && (*srclen >= 3)) { // three bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- *src += 3;
- *srclen -= 3;
- }else if (((c & 0xf8) == 0xf0) && (*srclen >= 4)) { // four bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[3]];
- *src += 4;
- *srclen -= 4;
- } else { // Ill-formed
- e = 0;
- *src += 1;
- *srclen -= 1;
- }
- return e;
-}
-
-// TwoByte versions are needed for tables > 240 states
-bool UTF8HasGenericPropertyTwoByte(const UTF8PropObj_2& st, const char* src) {
- const uint8* lsrc = reinterpret_cast<const uint8*>(src);
- const unsigned short* Tbl_0 = &st.state_table[st.state0];
- const unsigned short* Tbl = Tbl_0;
- int e;
- int eshift = st.entry_shift;
-
- // Short series of tests faster than switch, optimizes 7-bit ASCII
- unsigned char c = lsrc[0];
- if (static_cast<signed char>(c) >= 0) { // one byte
- e = Tbl[c];
- } else if ((c & 0xe0) == 0xc0) { // two bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- } else if ((c & 0xf0) == 0xe0) { // three bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- } else { // four bytes
- e = Tbl[c];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[1]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[2]];
- Tbl = &Tbl_0[e << eshift];
- e = Tbl[lsrc[3]];
- }
- return e;
-}
-
-
-// Approximate speeds on 2.8 GHz Pentium 4:
-// GenericScan 1-byte loop 300 MB/sec *
-// GenericScan 4-byte loop 1200 MB/sec
-// GenericScan 8-byte loop 2400 MB/sec *
-// GenericScanFastAscii 4-byte loop 3000 MB/sec
-// GenericScanFastAscii 8-byte loop 3200 MB/sec *
-//
-// * Implemented below. FastAscii loop is memory-bandwidth constrained.
-
-// Scan a UTF-8 stringpiece based on state table.
-// Always scan complete UTF-8 characters
-// Set number of bytes scanned. Return reason for exiting
-int UTF8GenericScan(const UTF8ScanObj* st,
- const StringPiece& str,
- int* bytes_consumed) {
- int eshift = st->entry_shift; // 6 (space optimized) or 8
- // int nEntries = (1 << eshift); // 64 or 256 entries per state
-
- const uint8* isrc =
- reinterpret_cast<const uint8*>(str.data());
- const uint8* src = isrc;
- const int len = str.length();
- const uint8* srclimit = isrc + len;
- const uint8* srclimit8 = srclimit - 7;
- *bytes_consumed = 0;
- if (len == 0) return kExitOK;
-
- const uint8* Tbl_0 = &st->state_table[st->state0];
-
-DoAgain:
- // Do state-table scan
- int e = 0;
- uint8 c;
-
- // Do fast for groups of 8 identity bytes.
- // This covers a lot of 7-bit ASCII ~8x faster than the 1-byte loop,
- // including slowing slightly on cr/lf/ht
- //----------------------------
- const uint8* Tbl2 = &st->fast_state[0];
- uint32 losub = st->losub;
- uint32 hiadd = st->hiadd;
- while (src < srclimit8) {
- uint32 s0123 = (reinterpret_cast<const uint32 *>(src))[0];
- uint32 s4567 = (reinterpret_cast<const uint32 *>(src))[1];
- src += 8;
- // This is a fast range check for all bytes in [lowsub..0x80-hiadd)
- uint32 temp = (s0123 - losub) | (s0123 + hiadd) |
- (s4567 - losub) | (s4567 + hiadd);
- if ((temp & 0x80808080) != 0) {
- // We typically end up here on cr/lf/ht; src was incremented
- int e0123 = (Tbl2[src[-8]] | Tbl2[src[-7]]) |
- (Tbl2[src[-6]] | Tbl2[src[-5]]);
- if (e0123 != 0) {src -= 8; break;} // Exit on Non-interchange
- e0123 = (Tbl2[src[-4]] | Tbl2[src[-3]]) |
- (Tbl2[src[-2]] | Tbl2[src[-1]]);
- if (e0123 != 0) {src -= 4; break;} // Exit on Non-interchange
- // Else OK, go around again
- }
- }
- //----------------------------
-
- // Byte-at-a-time scan
- //----------------------------
- const uint8* Tbl = Tbl_0;
- while (src < srclimit) {
- c = *src;
- e = Tbl[c];
- src++;
- if (e >= kExitIllegalStructure) {break;}
- Tbl = &Tbl_0[e << eshift];
- }
- //----------------------------
-
-
- // Exit possibilities:
- // Some exit code, !state0, back up over last char
- // Some exit code, state0, back up one byte exactly
- // source consumed, !state0, back up over partial char
- // source consumed, state0, exit OK
- // For illegal byte in state0, avoid backup up over PREVIOUS char
- // For truncated last char, back up to beginning of it
-
- if (e >= kExitIllegalStructure) {
- // Back up over exactly one byte of rejected/illegal UTF-8 character
- src--;
- // Back up more if needed
- if (!InStateZero(st, Tbl)) {
- do {src--;} while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
- }
- } else if (!InStateZero(st, Tbl)) {
- // Back up over truncated UTF-8 character
- e = kExitIllegalStructure;
- do {src--;} while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
- } else {
- // Normal termination, source fully consumed
- e = kExitOK;
- }
-
- if (e == kExitDoAgain) {
- // Loop back up to the fast scan
- goto DoAgain;
- }
-
- *bytes_consumed = src - isrc;
- return e;
-}
-
-// Scan a UTF-8 stringpiece based on state table.
-// Always scan complete UTF-8 characters
-// Set number of bytes scanned. Return reason for exiting
-// OPTIMIZED for case of 7-bit ASCII 0000..007f all valid
-int UTF8GenericScanFastAscii(const UTF8ScanObj* st,
- const StringPiece& str,
- int* bytes_consumed) {
- const uint8* isrc =
- reinterpret_cast<const uint8*>(str.data());
- const uint8* src = isrc;
- const int len = str.length();
- const uint8* srclimit = isrc + len;
- const uint8* srclimit8 = srclimit - 7;
- *bytes_consumed = 0;
- if (len == 0) return kExitOK;
-
- int n;
- int rest_consumed;
- int exit_reason;
- do {
- // Skip 8 bytes of ASCII at a whack; no endianness issue
- while ((src < srclimit8) &&
- (((reinterpret_cast<const uint32*>(src)[0] |
- reinterpret_cast<const uint32*>(src)[1]) & 0x80808080) == 0)) {
- src += 8;
- }
- // Run state table on the rest
- n = src - isrc;
- StringPiece str2(str.data() + n, str.length() - n);
- exit_reason = UTF8GenericScan(st, str2, &rest_consumed);
- src += rest_consumed;
- } while ( exit_reason == kExitDoAgain );
-
- *bytes_consumed = src - isrc;
- return exit_reason;
-}
-
-// Hack to change halfwidth katakana to match an old UTF8CharToLower()
-
-// Return number of src bytes skipped
-static int DoSpecialFixup(const unsigned char c,
- const unsigned char** srcp, const unsigned char* srclimit,
- unsigned char** dstp, unsigned char* dstlimit) {
- return 0;
-}
-
-
-// Scan a UTF-8 stringpiece based on state table, copying to output stringpiece
-// and doing text replacements.
-// DO NOT CALL DIRECTLY. Use UTF8GenericReplace() below
-// Needs caller to loop on kExitDoAgain
-static int UTF8GenericReplaceInternal(const UTF8ReplaceObj* st,
- const StringPiece& istr,
- StringPiece& ostr,
- bool is_plain_text,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed,
- OffsetMap* offsetmap) {
- int eshift = st->entry_shift;
- int nEntries = (1 << eshift); // 64 or 256 entries per state
- const uint8* isrc = reinterpret_cast<const uint8*>(istr.data());
- const int ilen = istr.length();
- const uint8* copystart = isrc;
- const uint8* src = isrc;
- const uint8* srclimit = src + ilen;
- *bytes_consumed = 0;
- *bytes_filled = 0;
- *chars_changed = 0;
-
- const uint8* odst = reinterpret_cast<const uint8*>(ostr.data());
- const int olen = ostr.length();
- uint8* dst = const_cast<uint8*>(odst);
- uint8* dstlimit = dst + olen;
-
- int total_changed = 0;
-
- // Invariant condition during replacements:
- // remaining dst size >= remaining src size
- if ((dstlimit - dst) < (srclimit - src)) {
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart);
- copystart = src;
- }
- return kExitDstSpaceFull;
- }
- const uint8* Tbl_0 = &st->state_table[st->state0];
-
- Do_state_table:
- // Do state-table scan, copying as we go
- const uint8* Tbl = Tbl_0;
- int e = 0;
- uint8 c = 0;
-
- Do_state_table_newe:
-
- //----------------------------
- while (src < srclimit) {
- c = *src;
- e = Tbl[c];
- *dst = c;
- src++;
- dst++;
- if (e >= kExitIllegalStructure) {break;}
- Tbl = &Tbl_0[e << eshift];
- }
- //----------------------------
-
- // Exit possibilities:
- // Replacement code, do the replacement and loop
- // Some other exit code, state0, back up one byte exactly
- // Some other exit code, !state0, back up over last char
- // source consumed, state0, exit OK
- // source consumed, !state0, back up over partial char
- // For illegal byte in state0, avoid backup up over PREVIOUS char
- // For truncated last char, back up to beginning of it
-
- if (e >= kExitIllegalStructure) {
- // Switch on exit code; most loop back to top
- int offset = 0;
- switch (e) {
- // These all make the output string the same size or shorter
- // No checking needed
- case kExitReplace31: // del 2, add 1 bytes to change
- dst -= 2;
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart - 2);
- offsetmap->Delete(2);
- copystart = src;
- }
- dst[-1] = (unsigned char)Tbl[c + (nEntries * 1)];
- total_changed++;
- goto Do_state_table;
- case kExitReplace32: // del 3, add 2 bytes to change
- dst--;
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart - 1);
- offsetmap->Delete(1);
- copystart = src;
- }
- dst[-2] = (unsigned char)Tbl[c + (nEntries * 2)];
- dst[-1] = (unsigned char)Tbl[c + (nEntries * 1)];
- total_changed++;
- goto Do_state_table;
- case kExitReplace21: // del 2, add 1 bytes to change
- dst--;
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart - 1);
- offsetmap->Delete(1);
- copystart = src;
- }
- dst[-1] = (unsigned char)Tbl[c + (nEntries * 1)];
- total_changed++;
- goto Do_state_table;
- case kExitReplace3: // update 3 bytes to change
- dst[-3] = (unsigned char)Tbl[c + (nEntries * 3)];
- // Fall into next case
- case kExitReplace2: // update 2 bytes to change
- dst[-2] = (unsigned char)Tbl[c + (nEntries * 2)];
- // Fall into next case
- case kExitReplace1: // update 1 byte to change
- dst[-1] = (unsigned char)Tbl[c + (nEntries * 1)];
- total_changed++;
- goto Do_state_table;
- case kExitReplace1S0: // update 1 byte to change, 256-entry state
- dst[-1] = (unsigned char)Tbl[c + (256 * 1)];
- total_changed++;
- goto Do_state_table;
- // These can make the output string longer than the input
- case kExitReplaceOffset2:
- if ((nEntries != 256) && InStateZero(st, Tbl)) {
- // For space-optimized table, we need multiples of 256 bytes
- // in state0 and multiples of nEntries in other states
- offset += ((unsigned char)Tbl[c + (256 * 2)] << 8);
- } else {
- offset += ((unsigned char)Tbl[c + (nEntries * 2)] << 8);
- }
- // Fall into next case
- case kExitSpecial: // Apply special fixups [read: hacks]
- case kExitReplaceOffset1:
- if ((nEntries != 256) && InStateZero(st, Tbl)) {
- // For space-optimized table, we need multiples of 256 bytes
- // in state0 and multiples of nEntries in other states
- offset += (unsigned char)Tbl[c + (256 * 1)];
- } else {
- offset += (unsigned char)Tbl[c + (nEntries * 1)];
- }
- {
- const RemapEntry* re = &st->remap_base[offset];
- int del_len = re->delete_bytes & ~kReplaceAndResumeFlag;
- int add_len = re->add_bytes & ~kHtmlPlaintextFlag;
-
- // Special-case non-HTML replacement of five sensitive entities
- // &quot; &amp; &apos; &lt; &gt;
- // 0022 0026 0027 003c 003e
- // A replacement creating one of these is expressed as a pair of
- // entries, one for HTML output and one for plaintext output.
- // The first of the pair has the high bit of add_bytes set.
- if (re->add_bytes & kHtmlPlaintextFlag) {
- // Use this entry for plain text
- if (!is_plain_text) {
- // Use very next entry for HTML text (same back/delete length)
- re = &st->remap_base[offset + 1];
- add_len = re->add_bytes & ~kHtmlPlaintextFlag;
- }
- }
-
- int string_offset = re->bytes_offset;
- // After the replacement, need (dstlimit - newdst) >= (srclimit - src)
- uint8* newdst = dst - del_len + add_len;
- if ((dstlimit - newdst) < (srclimit - src)) {
- // Won't fit; don't do the replacement. Caller may realloc and retry
- e = kExitDstSpaceFull;
- break; // exit, backing up over this char for later retry
- }
- dst -= del_len;
- memcpy(dst, &st->remap_string[string_offset], add_len);
- dst += add_len;
- total_changed++;
- if (offsetmap != NULL) {
- if (add_len > del_len) {
- offsetmap->Copy(src - copystart);
- offsetmap->Insert(add_len - del_len);
- copystart = src;
- } else if (add_len < del_len) {
- offsetmap->Copy(src - copystart + add_len - del_len);
- offsetmap->Delete(del_len - add_len);
- copystart = src;
- }
- }
- if (re->delete_bytes & kReplaceAndResumeFlag) {
- // There is a non-zero target state at the end of the
- // replacement string
- e = st->remap_string[string_offset + add_len];
- Tbl = &Tbl_0[e << eshift];
- goto Do_state_table_newe;
- }
- }
- if (e == kExitRejectAlt) {break;}
- if (e != kExitSpecial) {goto Do_state_table;}
-
- // case kExitSpecial: // Apply special fixups [read: hacks]
- // In this routine, do either UTF8CharToLower()
- // fullwidth/halfwidth mapping or
- // voiced mapping or
- // semi-voiced mapping
-
- // First, do EXIT_REPLACE_OFFSET1 action (above)
- // Second: do additional code fixup
- {
- int srcdel = DoSpecialFixup(c, &src, srclimit, &dst, dstlimit);
- if (offsetmap != NULL) {
- if (srcdel != 0) {
- offsetmap->Copy(src - copystart - srcdel);
- offsetmap->Delete(srcdel);
- copystart = src;
- }
- }
- }
- goto Do_state_table;
-
- case kExitIllegalStructure: // structurally illegal byte; quit
- case kExitReject: // NUL or illegal code encountered; quit
- case kExitRejectAlt: // Apply replacement, then exit
- default: // and all other exits
- break;
- } // End switch (e)
-
- // Exit possibilities:
- // Some other exit code, state0, back up one byte exactly
- // Some other exit code, !state0, back up over last char
-
- // Back up over exactly one byte of rejected/illegal UTF-8 character
- src--;
- dst--;
- // Back up more if needed
- if (!InStateZero(st, Tbl)) {
- do {src--;dst--;} while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
- }
- } else if (!InStateZero(st, Tbl)) {
- // src >= srclimit, !state0
- // Back up over truncated UTF-8 character
- e = kExitIllegalStructure;
- do {src--; dst--;} while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
- } else {
- // src >= srclimit, state0
- // Normal termination, source fully consumed
- e = kExitOK;
- }
-
- if (offsetmap != NULL) {
- if (src > copystart) {
- offsetmap->Copy(src - copystart);
- copystart = src;
- }
- }
-
- // Possible return values here:
- // kExitDstSpaceFull caller may realloc and retry from middle
- // kExitIllegalStructure caller my overwrite/truncate
- // kExitOK all done and happy
- // kExitReject caller may overwrite/truncate
- // kExitDoAgain LOOP NOT DONE; caller must retry from middle
- // (may do fast ASCII loop first)
- // kExitPlaceholder -unused-
- // kExitNone -unused-
- *bytes_consumed = src - isrc;
- *bytes_filled = dst - odst;
- *chars_changed = total_changed;
- return e;
-}
-
-// TwoByte versions are needed for tables > 240 states, such
-// as the table for full Unicode 4.1 canonical + compatibility mapping
-
-// Scan a UTF-8 stringpiece based on state table with two-byte entries,
-// copying to output stringpiece
-// and doing text replacements.
-// DO NOT CALL DIRECTLY. Use UTF8GenericReplace() below
-// Needs caller to loop on kExitDoAgain
-static int UTF8GenericReplaceInternalTwoByte(const UTF8ReplaceObj_2* st,
- const StringPiece& istr,
- StringPiece& ostr,
- bool is_plain_text,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed,
- OffsetMap* offsetmap) {
- int eshift = st->entry_shift;
- int nEntries = (1 << eshift); // 64 or 256 entries per state
- const uint8* isrc = reinterpret_cast<const uint8*>(istr.data());
- const int ilen = istr.length();
- const uint8* copystart = isrc;
- const uint8* src = isrc;
- const uint8* srclimit = src + ilen;
- *bytes_consumed = 0;
- *bytes_filled = 0;
- *chars_changed = 0;
-
- const uint8* odst = reinterpret_cast<const uint8*>(ostr.data());
- const int olen = ostr.length();
- uint8* dst = const_cast<uint8*>(odst);
- uint8* dstlimit = dst + olen;
-
- *chars_changed = 0;
-
- int total_changed = 0;
-
- int src_lll = srclimit - src;
- int dst_lll = dstlimit - dst;
-
-
- // Invariant condition during replacements:
- // remaining dst size >= remaining src size
- if ((dstlimit - dst) < (srclimit - src)) {
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart);
- copystart = src;
- }
- return kExitDstSpaceFull_2;
- }
- const unsigned short* Tbl_0 = &st->state_table[st->state0];
-
- Do_state_table_2:
- // Do state-table scan, copying as we go
- const unsigned short* Tbl = Tbl_0;
- int e = 0;
- uint8 c = 0;
-
- Do_state_table_newe_2:
-
- //----------------------------
- while (src < srclimit) {
- c = *src;
- e = Tbl[c];
- *dst = c;
- src++;
- dst++;
- if (e >= kExitIllegalStructure_2) {break;}
- Tbl = &Tbl_0[e << eshift];
- }
- //----------------------------
- src_lll = src - isrc;
- dst_lll = dst - odst;
-
- // Exit possibilities:
- // Replacement code, do the replacement and loop
- // Some other exit code, state0, back up one byte exactly
- // Some other exit code, !state0, back up over last char
- // source consumed, state0, exit OK
- // source consumed, !state0, back up over partial char
- // For illegal byte in state0, avoid backup up over PREVIOUS char
- // For truncated last char, back up to beginning of it
-
- if (e >= kExitIllegalStructure_2) {
- // Switch on exit code; most loop back to top
- int offset = 0;
- switch (e) {
- // These all make the output string the same size or shorter
- // No checking needed
- case kExitReplace31_2: // del 2, add 1 bytes to change
- dst -= 2;
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart - 2);
- offsetmap->Delete(2);
- copystart = src;
- }
- dst[-1] = (unsigned char)(Tbl[c + (nEntries * 1)] & 0xff);
- total_changed++;
- goto Do_state_table_2;
- case kExitReplace32_2: // del 3, add 2 bytes to change
- dst--;
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart - 1);
- offsetmap->Delete(1);
- copystart = src;
- }
- dst[-2] = (unsigned char)(Tbl[c + (nEntries * 1)] >> 8 & 0xff);
- dst[-1] = (unsigned char)(Tbl[c + (nEntries * 1)] & 0xff);
- total_changed++;
- goto Do_state_table_2;
- case kExitReplace21_2: // del 2, add 1 bytes to change
- dst--;
- if (offsetmap != NULL) {
- offsetmap->Copy(src - copystart - 1);
- offsetmap->Delete(1);
- copystart = src;
- }
- dst[-1] = (unsigned char)(Tbl[c + (nEntries * 1)] & 0xff);
- total_changed++;
- goto Do_state_table_2;
- case kExitReplace3_2: // update 3 bytes to change
- dst[-3] = (unsigned char)(Tbl[c + (nEntries * 2)] & 0xff);
- // Fall into next case
- case kExitReplace2_2: // update 2 bytes to change
- dst[-2] = (unsigned char)(Tbl[c + (nEntries * 1)] >> 8 & 0xff);
- // Fall into next case
- case kExitReplace1_2: // update 1 byte to change
- dst[-1] = (unsigned char)(Tbl[c + (nEntries * 1)] & 0xff);
- total_changed++;
- goto Do_state_table_2;
- case kExitReplace1S0_2: // update 1 byte to change, 256-entry state
- dst[-1] = (unsigned char)(Tbl[c + (256 * 1)] & 0xff);
- total_changed++;
- goto Do_state_table_2;
- // These can make the output string longer than the input
- case kExitReplaceOffset2_2:
- if ((nEntries != 256) && InStateZero_2(st, Tbl)) {
- // For space-optimized table, we need multiples of 256 bytes
- // in state0 and multiples of nEntries in other states
- offset += ((unsigned char)(Tbl[c + (256 * 1)] >> 8 & 0xff) << 8);
- } else {
- offset += ((unsigned char)(Tbl[c + (nEntries * 1)] >> 8 & 0xff) << 8);
- }
- // Fall into next case
- case kExitReplaceOffset1_2:
- if ((nEntries != 256) && InStateZero_2(st, Tbl)) {
- // For space-optimized table, we need multiples of 256 bytes
- // in state0 and multiples of nEntries in other states
- offset += (unsigned char)(Tbl[c + (256 * 1)] & 0xff);
- } else {
- offset += (unsigned char)(Tbl[c + (nEntries * 1)] & 0xff);
- }
- {
- const RemapEntry* re = &st->remap_base[offset];
- int del_len = re->delete_bytes & ~kReplaceAndResumeFlag;
- int add_len = re->add_bytes & ~kHtmlPlaintextFlag;
- // Special-case non-HTML replacement of five sensitive entities
- // &quot; &amp; &apos; &lt; &gt;
- // 0022 0026 0027 003c 003e
- // A replacement creating one of these is expressed as a pair of
- // entries, one for HTML output and one for plaintext output.
- // The first of the pair has the high bit of add_bytes set.
- if (re->add_bytes & kHtmlPlaintextFlag) {
- // Use this entry for plain text
- if (!is_plain_text) {
- // Use very next entry for HTML text (same back/delete length)
- re = &st->remap_base[offset + 1];
- add_len = re->add_bytes & ~kHtmlPlaintextFlag;
- }
- }
-
- // After the replacement, need (dstlimit - dst) >= (srclimit - src)
- int string_offset = re->bytes_offset;
- // After the replacement, need (dstlimit - newdst) >= (srclimit - src)
- uint8* newdst = dst - del_len + add_len;
- if ((dstlimit - newdst) < (srclimit - src)) {
- // Won't fit; don't do the replacement. Caller may realloc and retry
- e = kExitDstSpaceFull_2;
- break; // exit, backing up over this char for later retry
- }
- dst -= del_len;
- memcpy(dst, &st->remap_string[string_offset], add_len);
- dst += add_len;
- if (offsetmap != NULL) {
- if (add_len > del_len) {
- offsetmap->Copy(src - copystart);
- offsetmap->Insert(add_len - del_len);
- copystart = src;
- } else if (add_len < del_len) {
- offsetmap->Copy(src - copystart + add_len - del_len);
- offsetmap->Delete(del_len - add_len);
- copystart = src;
- }
- }
- if (re->delete_bytes & kReplaceAndResumeFlag) {
- // There is a two-byte non-zero target state at the end of the
- // replacement string
- uint8 c1 = st->remap_string[string_offset + add_len];
- uint8 c2 = st->remap_string[string_offset + add_len + 1];
- e = (c1 << 8) | c2;
- Tbl = &Tbl_0[e << eshift];
- total_changed++;
- goto Do_state_table_newe_2;
- }
- }
- total_changed++;
- if (e == kExitRejectAlt_2) {break;}
- goto Do_state_table_2;
-
- case kExitSpecial_2: // NO special fixups [read: hacks]
- case kExitIllegalStructure_2: // structurally illegal byte; quit
- case kExitReject_2: // NUL or illegal code encountered; quit
- // and all other exits
- default:
- break;
- } // End switch (e)
-
- // Exit possibilities:
- // Some other exit code, state0, back up one byte exactly
- // Some other exit code, !state0, back up over last char
-
- // Back up over exactly one byte of rejected/illegal UTF-8 character
- src--;
- dst--;
- // Back up more if needed
- if (!InStateZero_2(st, Tbl)) {
- do {src--;dst--;} while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
- }
- } else if (!InStateZero_2(st, Tbl)) {
- // src >= srclimit, !state0
- // Back up over truncated UTF-8 character
- e = kExitIllegalStructure_2;
-
- do {src--; dst--;} while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
- } else {
- // src >= srclimit, state0
- // Normal termination, source fully consumed
- e = kExitOK_2;
- }
-
- if (offsetmap != NULL) {
- if (src > copystart) {
- offsetmap->Copy(src - copystart);
- copystart = src;
- }
- }
-
-
- // Possible return values here:
- // kExitDstSpaceFull_2 caller may realloc and retry from middle
- // kExitIllegalStructure_2 caller my overwrite/truncate
- // kExitOK_2 all done and happy
- // kExitReject_2 caller may overwrite/truncate
- // kExitDoAgain_2 LOOP NOT DONE; caller must retry from middle
- // (may do fast ASCII loop first)
- // kExitPlaceholder_2 -unused-
- // kExitNone_2 -unused-
- *bytes_consumed = src - isrc;
- *bytes_filled = dst - odst;
- *chars_changed = total_changed;
- return e;
-}
-
-
-// Scan a UTF-8 stringpiece based on state table, copying to output stringpiece
-// and doing text replacements.
-// Also writes an optional OffsetMap. Pass NULL to skip writing one.
-// Always scan complete UTF-8 characters
-// Set number of bytes consumed from input, number filled to output.
-// Return reason for exiting
-int UTF8GenericReplace(const UTF8ReplaceObj* st,
- const StringPiece& istr,
- StringPiece& ostr,
- bool is_plain_text,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed,
- OffsetMap* offsetmap) {
- StringPiece local_istr(istr.data(), istr.length());
- StringPiece local_ostr(ostr.data(), ostr.length());
- int total_consumed = 0;
- int total_filled = 0;
- int total_changed = 0;
- int local_bytes_consumed, local_bytes_filled, local_chars_changed;
- int e;
- do {
- e = UTF8GenericReplaceInternal(st,
- local_istr, local_ostr, is_plain_text,
- &local_bytes_consumed, &local_bytes_filled,
- &local_chars_changed,
- offsetmap);
- local_istr.remove_prefix(local_bytes_consumed);
- local_ostr.remove_prefix(local_bytes_filled);
- total_consumed += local_bytes_consumed;
- total_filled += local_bytes_filled;
- total_changed += local_chars_changed;
- } while ( e == kExitDoAgain );
- *bytes_consumed = total_consumed;
- *bytes_filled = total_filled;
- *chars_changed = total_changed;
- return e;
-}
-
-// Older version without offsetmap
-int UTF8GenericReplace(const UTF8ReplaceObj* st,
- const StringPiece& istr,
- StringPiece& ostr,
- bool is_plain_text,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed) {
- return UTF8GenericReplace(st,
- istr,
- ostr,
- is_plain_text,
- bytes_consumed,
- bytes_filled,
- chars_changed,
- NULL);
-}
-
-// Older version without is_plain_text or offsetmap
-int UTF8GenericReplace(const UTF8ReplaceObj* st,
- const StringPiece& istr,
- StringPiece& ostr,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed) {
- bool is_plain_text = false;
- return UTF8GenericReplace(st,
- istr,
- ostr,
- is_plain_text,
- bytes_consumed,
- bytes_filled,
- chars_changed,
- NULL);
-}
-
-// Scan a UTF-8 stringpiece based on state table with two-byte entries,
-// copying to output stringpiece
-// and doing text replacements.
-// Also writes an optional OffsetMap. Pass NULL to skip writing one.
-// Always scan complete UTF-8 characters
-// Set number of bytes consumed from input, number filled to output.
-// Return reason for exiting
-int UTF8GenericReplaceTwoByte(const UTF8ReplaceObj_2* st,
- const StringPiece& istr,
- StringPiece& ostr,
- bool is_plain_text,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed,
- OffsetMap* offsetmap) {
- StringPiece local_istr(istr.data(), istr.length());
- StringPiece local_ostr(ostr.data(), ostr.length());
- int total_consumed = 0;
- int total_filled = 0;
- int total_changed = 0;
- int local_bytes_consumed, local_bytes_filled, local_chars_changed;
- int e;
- do {
- e = UTF8GenericReplaceInternalTwoByte(st,
- local_istr, local_ostr, is_plain_text,
- &local_bytes_consumed,
- &local_bytes_filled,
- &local_chars_changed,
- offsetmap);
- local_istr.remove_prefix(local_bytes_consumed);
- local_ostr.remove_prefix(local_bytes_filled);
- total_consumed += local_bytes_consumed;
- total_filled += local_bytes_filled;
- total_changed += local_chars_changed;
- } while ( e == kExitDoAgain_2 );
- *bytes_consumed = total_consumed;
- *bytes_filled = total_filled;
- *chars_changed = total_changed;
-
- return e - kExitOK_2 + kExitOK;
-}
-
-// Older version without offsetmap
-int UTF8GenericReplaceTwoByte(const UTF8ReplaceObj_2* st,
- const StringPiece& istr,
- StringPiece& ostr,
- bool is_plain_text,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed) {
- return UTF8GenericReplaceTwoByte(st,
- istr,
- ostr,
- is_plain_text,
- bytes_consumed,
- bytes_filled,
- chars_changed,
- NULL);
-}
-
-// Older version without is_plain_text or offsetmap
-int UTF8GenericReplaceTwoByte(const UTF8ReplaceObj_2* st,
- const StringPiece& istr,
- StringPiece& ostr,
- int* bytes_consumed,
- int* bytes_filled,
- int* chars_changed) {
- bool is_plain_text = false;
- return UTF8GenericReplaceTwoByte(st,
- istr,
- ostr,
- is_plain_text,
- bytes_consumed,
- bytes_filled,
- chars_changed,
- NULL);
-}
-
-
-
-// Adjust a stringpiece to encompass complete UTF-8 characters.
-// The data pointer will be increased by 0..3 bytes to get to a character
-// boundary, and the length will then be decreased by 0..3 bytes
-// to encompass the last complete character.
-void UTF8TrimToChars(StringPiece* istr) {
- const char* src = istr->data();
- int len = istr->length();
- // Exit if empty string
- if (len == 0) {
- return;
- }
-
- // Exit on simple, common case
- if ( ((src[0] & 0xc0) != 0x80) &&
- (static_cast<signed char>(src[len - 1]) >= 0) ) {
- // First byte is not a continuation and last byte is 7-bit ASCII -- done
- return;
- }
-
- // Adjust the back end, len > 0
- const char* srclimit = src + len;
- // Backscan over any ending continuation bytes to find last char start
- const char* s = srclimit - 1; // Last byte of the string
- while ((src <= s) && ((*s & 0xc0) == 0x80)) {
- s--;
- }
- // Include entire last char if it fits
- if (src <= s) {
- int last_char_len = UTF8OneCharLen(s);
- if (s + last_char_len <= srclimit) {
- // Last char fits, so include it, else exclude it
- s += last_char_len;
- }
- }
- if (s != srclimit) {
- // s is one byte beyond the last full character, if any
- istr->remove_suffix(srclimit - s);
- // Exit if now empty string
- if (istr->length() == 0) {
- return;
- }
- }
-
- // Adjust the front end, len > 0
- len = istr->length();
- srclimit = src + len;
- s = src; // First byte of the string
- // Scan over any beginning continuation bytes to find first char start
- while ((s < srclimit) && ((*s & 0xc0) == 0x80)) {
- s++;
- }
- if (s != src) {
- // s is at the first full character, if any
- istr->remove_prefix(s - src);
- }
-}
-
-} // End namespace CLD2
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 19:00:10 +0000