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f6118acda9
Moving these members: CHARSET_INFO *cs; const MY_UCA_WEIGHT_LEVEL *level; from my_uca_scanner to a new separate structure my_uca_scanner_param. Rationale: During a comparison of two strings these members were initialized two times (one time for every string). After the change these members initialized only one time inside a shared instance of my_uca_scanner_param, and the instance is shared between two scanners (its const address is passed as new a parameter to the underlying scanner functions). This change gives a slight performance improvement (~5%).
224 lines
7.6 KiB
C++
224 lines
7.6 KiB
C++
/* Copyright (c) 2004, 2013, Oracle and/or its affiliates.
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Copyright (c) 2009, 2021, MariaDB
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public
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License as published by the Free Software Foundation; version 2
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of the License.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this library; if not, write to the Free
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Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
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MA 02110-1335 USA */
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#ifdef SCANNER_NEXT_NCHARS
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#define SCANNER_NEXT_RETURN(_w,_n) \
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do { weight_and_nchars_t rc= {_w, _n}; return rc; } while(0)
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#define SCANNER_NEXT_RETURN_CONTRACTION(_cnt,_ignorable_nchars) \
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do { \
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weight_and_nchars_t rc= { _cnt->weight[0], \
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_ignorable_nchars + \
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my_contraction_char_length(_cnt) }; \
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return rc; \
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} while(0)
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#else
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#define SCANNER_NEXT_RETURN(_w,_n) do { return _w; } while (0)
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#define SCANNER_NEXT_RETURN_CONTRACTION(_cnt,_ignorable_nchars) \
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do { return _cnt->weight[0]; } while(0)
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#endif
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static inline
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#ifdef SCANNER_NEXT_NCHARS
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weight_and_nchars_t
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MY_FUNCTION_NAME(scanner_next_with_nchars)(my_uca_scanner *scanner,
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const my_uca_scanner_param *param,
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size_t nchars)
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#else
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int
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MY_FUNCTION_NAME(scanner_next)(my_uca_scanner *scanner,
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const my_uca_scanner_param *param)
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#endif
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{
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#ifdef SCANNER_NEXT_NCHARS
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uint ignorable_nchars;
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#define LOCAL_MAX_CONTRACTION_LENGTH nchars
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#else
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#define LOCAL_MAX_CONTRACTION_LENGTH MY_UCA_MAX_CONTRACTION
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#endif
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uint16 weight= my_uca_scanner_next_expansion_weight(scanner);
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if (weight)
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{
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/*
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More weights left from the previous step.
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Return the next weight from the current expansion.
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Return "0" as "nchars". The real nchars was set on a previous
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iteration.
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*/
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SCANNER_NEXT_RETURN(weight, 0);
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}
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#ifdef SCANNER_NEXT_NCHARS
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for (ignorable_nchars= 0 ; ; ignorable_nchars++)
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#else
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for ( ; ; )
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#endif
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{
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const uint16 *wpage;
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int mblen;
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my_wc_t currwc= 0;
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const uint16 *cweight;
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#if MY_UCA_ASCII_OPTIMIZE && !defined(SCANNER_NEXT_NCHARS)
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if (scanner->sbeg + 1 < scanner->send)
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{
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const MY_UCA_2BYTES_ITEM *ww;
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ww= my_uca_level_booster_2bytes_item_addr_const(param->level->booster,
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scanner->sbeg[0],
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scanner->sbeg[1]);
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if (my_uca_2bytes_item_is_applicable(ww))
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{
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/*
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Byte pairs that make 2-byte head characters in previous
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context pairs are marked as not applicable for optimization
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during the collation initialization. So when we come here
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sbeg[0] and sbeg[1] are:
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- either two ASCII characters
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- or one 2-byte character which IS NOT a previous context head
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Just remember sbeg[1] as the previous character for simplicity.
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This may erroneously interpret bytes 0x80..0x9F as previous context
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head characters U+0080..U+009F. However, CLDR does not have any real
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collations that use these characters as previous context heads.
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*/
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scanner->page= 0;
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scanner->code= (int) scanner->sbeg[1];
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scanner->sbeg+= 2;
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if ((weight= my_uca_scanner_set_weight(scanner, ww->weight)))
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{
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/*
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TODO: add support for scanner_next_with_nchars and do this:
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SCANNER_NEXT_RETURN(weight, ignorable_nchars + 1);
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*/
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return weight;
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}
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continue; /* Ignorable character */
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}
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/* 2 byte optimization is not applicable, go the slow path */
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}
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#endif
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/* Get next character */
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#if MY_UCA_ASCII_OPTIMIZE
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/* Get next ASCII character */
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if (scanner->sbeg < scanner->send && scanner->sbeg[0] < 0x80)
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{
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currwc= scanner->sbeg[0];
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scanner->sbeg+= 1;
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#if MY_UCA_COMPILE_CONTRACTIONS
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if (my_uca_needs_context_handling(param->level, currwc))
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{
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const MY_CONTRACTION *cnt= my_uca_context_weight_find(scanner, param,
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currwc,
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LOCAL_MAX_CONTRACTION_LENGTH);
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if (cnt)
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{
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if ((weight= my_uca_scanner_set_weight(scanner, cnt->weight)))
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SCANNER_NEXT_RETURN_CONTRACTION(cnt, ignorable_nchars);
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continue; /* Ignorable contraction */
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}
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}
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#endif
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scanner->page= 0;
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scanner->code= (int) currwc;
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cweight= param->level->weights[0] + scanner->code * param->level->lengths[0];
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if ((weight= my_uca_scanner_set_weight(scanner, cweight)))
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SCANNER_NEXT_RETURN(weight, ignorable_nchars + 1);
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continue; /* Ignorable character */
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}
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else
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#endif
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/* Get next MB character */
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if (((mblen= MY_MB_WC(scanner, param, &currwc, scanner->sbeg,
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scanner->send)) <= 0))
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{
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if (scanner->sbeg >= scanner->send)
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{
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/* No more bytes, end of line reached */
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SCANNER_NEXT_RETURN(-1, ignorable_nchars);
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}
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/*
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There are some more bytes left. Non-positive mb_len means that
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we got an incomplete or a bad byte sequence. Consume mbminlen bytes.
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*/
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if ((scanner->sbeg+= param->cs->mbminlen) > scanner->send)
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{
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/* For safety purposes don't go beyond the string range. */
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scanner->sbeg= scanner->send;
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}
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/*
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Treat every complete or incomplete mbminlen unit as a weight which is
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greater than weight for any possible normal character.
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0xFFFF is greater than any possible weight in the UCA weight table.
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*/
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SCANNER_NEXT_RETURN(0xFFFF, ignorable_nchars + 1);
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}
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scanner->sbeg+= mblen;
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if (currwc > param->level->maxchar)
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{
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SCANNER_NEXT_RETURN(my_uca_scanner_set_weight_outside_maxchar(scanner),
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ignorable_nchars + 1);
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}
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#if MY_UCA_COMPILE_CONTRACTIONS
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if (my_uca_needs_context_handling(param->level, currwc))
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{
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const MY_CONTRACTION *cnt= my_uca_context_weight_find(scanner, param, currwc,
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LOCAL_MAX_CONTRACTION_LENGTH);
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if (cnt)
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{
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if ((weight= my_uca_scanner_set_weight(scanner, cnt->weight)))
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SCANNER_NEXT_RETURN_CONTRACTION(cnt, ignorable_nchars);
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continue; /* Ignorable contraction */
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}
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}
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#endif
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/* Process single character */
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scanner->page= currwc >> 8;
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scanner->code= currwc & 0xFF;
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/* If weight page for w[0] does not exist, then calculate algoritmically */
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if (!(wpage= param->level->weights[scanner->page]))
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SCANNER_NEXT_RETURN(my_uca_scanner_next_implicit(scanner, param),
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ignorable_nchars + 1);
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/* Calculate pointer to w[0]'s weight, using page and offset */
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cweight= wpage + scanner->code * param->level->lengths[scanner->page];
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if ((weight= my_uca_scanner_set_weight(scanner, cweight)))
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SCANNER_NEXT_RETURN(weight, ignorable_nchars + 1);
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continue; /* Ignorable character */
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}
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SCANNER_NEXT_RETURN(0, 0); /* Not reachable */
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}
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#undef SCANNER_NEXT_NCHARS
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#undef SCANNER_NEXT_RETURN
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#undef SCANNER_NEXT_RETURN_CONTRACTION
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#undef LOCAL_MAX_CONTRACTION_LENGTH
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