Mercurial > hg > octave-kai > gnulib-hg
changeset 11202:016a9992938f
New module 'uninorm/filter'.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sat, 21 Feb 2009 15:51:29 +0100 |
parents | 46da6d119a43 |
children | cdae812b8b5a |
files | ChangeLog lib/uninorm.h lib/uninorm/uninorm-filter.c modules/uninorm/filter |
diffstat | 4 files changed, 444 insertions(+), 0 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2009-02-21 Bruno Haible <bruno@clisp.org> + + New module 'uninorm/filter'. + * lib/uninorm.h (uninorm_filter_create, uninorm_filter_write, + uninorm_filter_flush, uninorm_filter_free): New declarations. + * lib/uninorm/uninorm-filter.c: New file. + * modules/uninorm/filter: New file. + 2009-02-21 Bruno Haible <bruno@clisp.org> Tests for module 'uninorm/nfkc'.
--- a/lib/uninorm.h +++ b/lib/uninorm.h @@ -145,6 +145,48 @@ uint32_t *resultbuf, size_t *lengthp); +/* Normalization of a stream of Unicode characters. + + A "stream of Unicode characters" is essentially a function that accepts an + ucs4_t argument repeatedly, optionally combined with a function that + "flushes" the stream. */ + +/* Data type of a stream of Unicode characters that normalizes its input + according to a given normalization form and passes the normalized character + sequence to the encapsulated stream of Unicode characters. */ +struct uninorm_filter; + +/* Create and return a normalization filter for Unicode characters. + The pair (stream_func, stream_data) is the encapsulated stream. + stream_func (stream_data, uc) receives the Unicode character uc + and returns 0 if successful, or -1 with errno set upon failure. + Return the new filter, or NULL with errno set upon failure. */ +extern struct uninorm_filter * + uninorm_filter_create (uninorm_t nf, + int (*stream_func) (void *stream_data, ucs4_t uc), + void *stream_data); + +/* Stuff a Unicode character into a normalizing filter. + Return 0 if successful, or -1 with errno set upon failure. */ +extern int + uninorm_filter_write (struct uninorm_filter *filter, ucs4_t uc); + +/* Bring data buffered in the filter to its destination, the encapsulated + stream. + Return 0 if successful, or -1 with errno set upon failure. + Note! If after calling this function, additional characters are written + into the filter, the resulting character sequence in the encapsulated stream + will not necessarily be normalized. */ +extern int + uninorm_filter_flush (struct uninorm_filter *filter); + +/* Bring data buffered in the filter to its destination, the encapsulated + stream, then close and free the filter. + Return 0 if successful, or -1 with errno set upon failure. */ +extern int + uninorm_filter_free (struct uninorm_filter *filter); + + #ifdef __cplusplus } #endif
new file mode 100644 --- /dev/null +++ b/lib/uninorm/uninorm-filter.c @@ -0,0 +1,367 @@ +/* Stream-based normalization of Unicode strings. + Copyright (C) 2009 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2009. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include "uninorm.h" + +#include <errno.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> + +#include "unictype.h" +#include "normalize-internal.h" +#include "decompose-internal.h" + + +struct uninorm_filter +{ + /* Characteristics of the normalization form. */ + int (*decomposer) (ucs4_t uc, ucs4_t *decomposition); + ucs4_t (*composer) (ucs4_t uc1, ucs4_t uc2); + + /* The encapsulated stream. */ + int (*stream_func) (void *stream_data, ucs4_t uc); + void *stream_data; + + /* The buffer for sorting. */ + #define SORTBUF_PREALLOCATED 64 + struct ucs4_with_ccc sortbuf_preallocated[2 * SORTBUF_PREALLOCATED]; + struct ucs4_with_ccc *sortbuf; /* array of size 2 * sortbuf_allocated */ + size_t sortbuf_allocated; + size_t sortbuf_count; +}; + +struct uninorm_filter * +uninorm_filter_create (uninorm_t nf, + int (*stream_func) (void *stream_data, ucs4_t uc), + void *stream_data) +{ + struct uninorm_filter *filter = + (struct uninorm_filter *) malloc (sizeof (struct uninorm_filter)); + + if (filter == NULL) + /* errno is ENOMEM. */ + return NULL; + + filter->decomposer = nf->decomposer; + filter->composer = nf->composer; + filter->stream_func = stream_func; + filter->stream_data = stream_data; + filter->sortbuf = filter->sortbuf_preallocated; + filter->sortbuf_allocated = SORTBUF_PREALLOCATED; + filter->sortbuf_count = 0; + + return filter; +} + +int +uninorm_filter_write (struct uninorm_filter *filter, ucs4_t uc_arg) +{ + ucs4_t decomposed[UC_DECOMPOSITION_MAX_LENGTH]; + int decomposed_count; + + /* Accept the next character. */ + decomposed[0] = uc_arg; + decomposed_count = 1; + + /* Decompose it, recursively. + It would be possible to precompute the recursive decomposition + and store it in a table. But this would significantly increase + the size of the decomposition tables, because for example for + U+1FC1 the recursive canonical decomposition and the recursive + compatibility decomposition are different. */ + { + int curr; + + for (curr = 0; curr < decomposed_count; ) + { + /* Invariant: decomposed[0..curr-1] is fully decomposed, i.e. + all elements are atomic. */ + ucs4_t curr_decomposed[UC_DECOMPOSITION_MAX_LENGTH]; + int curr_decomposed_count; + + curr_decomposed_count = + filter->decomposer (decomposed[curr], curr_decomposed); + if (curr_decomposed_count >= 0) + { + /* Move curr_decomposed[0..curr_decomposed_count-1] over + decomposed[curr], making room. It's not worth using + memcpy() here, since the counts are so small. */ + int shift = curr_decomposed_count - 1; + + if (shift < 0) + abort (); + if (shift > 0) + { + int j; + + decomposed_count += shift; + if (decomposed_count > UC_DECOMPOSITION_MAX_LENGTH) + abort (); + for (j = decomposed_count - 1 - shift; j > curr; j--) + decomposed[j + shift] = decomposed[j]; + } + for (; shift >= 0; shift--) + decomposed[curr + shift] = curr_decomposed[shift]; + } + else + { + /* decomposed[curr] is atomic. */ + curr++; + } + } + } + + { + /* Cache sortbuf and sortbuf_count in local register variables. */ + struct ucs4_with_ccc * const sortbuf = filter->sortbuf; + size_t sortbuf_count = filter->sortbuf_count; + int i; + + for (i = 0; i < decomposed_count; i++) + { + /* Fetch the next character from the decomposition. */ + ucs4_t uc = decomposed[i]; + int ccc = uc_combining_class (uc); + + if (ccc == 0) + { + size_t j; + + /* Apply the canonical ordering algorithm to the accumulated + sequence of characters. */ + if (sortbuf_count > 1) + gl_uninorm_decompose_merge_sort_inplace (sortbuf, sortbuf_count, + sortbuf + sortbuf_count); + + if (filter->composer != NULL) + { + /* Attempt to combine decomposed characters, as specified + in the Unicode Standard Annex #15 "Unicode Normalization + Forms". We need to check + 1. whether the first accumulated character is a + "starter" (i.e. has ccc = 0). This is usually the + case. But when the string starts with a + non-starter, the sortbuf also starts with a + non-starter. Btw, this check could also be + omitted, because the composition table has only + entries (code1, code2) for which code1 is a + starter; if the first accumulated character is not + a starter, no lookup will succeed. + 2. If the sortbuf has more than one character, check + for each of these characters that are not "blocked" + from the starter (i.e. have a ccc that is higher + than the ccc of the previous character) whether it + can be combined with the first character. + 3. If only one character is left in sortbuf, check + whether it can be combined with the next character + (also a starter). */ + if (sortbuf_count > 0 && sortbuf[0].ccc == 0) + { + for (j = 1; j < sortbuf_count; ) + { + if (sortbuf[j].ccc > sortbuf[j - 1].ccc) + { + ucs4_t combined = + filter->composer (sortbuf[0].code, sortbuf[j].code); + if (combined) + { + size_t k; + + sortbuf[0].code = combined; + /* sortbuf[0].ccc = 0, still valid. */ + for (k = j + 1; k < sortbuf_count; k++) + sortbuf[k - 1] = sortbuf[k]; + sortbuf_count--; + continue; + } + } + j++; + } + if (sortbuf_count == 1) + { + ucs4_t combined = + filter->composer (sortbuf[0].code, uc); + if (combined) + { + uc = combined; + ccc = 0; + /* uc could be further combined with subsequent + characters. So don't put it into sortbuf[0] in + this round, only in the next round. */ + sortbuf_count = 0; + } + } + } + } + + for (j = 0; j < sortbuf_count; j++) + { + ucs4_t muc = sortbuf[j].code; + + /* Output muc to the encapsulated stream. */ + int ret = filter->stream_func (filter->stream_data, muc); + if (ret < 0) + { + /* errno is set here. */ + filter->sortbuf_count = 0; + return -1; + } + } + + /* sortbuf is now empty. */ + sortbuf_count = 0; + } + + /* Append (uc, ccc) to sortbuf. */ + if (sortbuf_count == filter->sortbuf_allocated) + { + struct ucs4_with_ccc *new_sortbuf; + + filter->sortbuf_allocated = 2 * filter->sortbuf_allocated; + if (filter->sortbuf_allocated < sortbuf_count) /* integer overflow? */ + abort (); + new_sortbuf = + (struct ucs4_with_ccc *) + malloc (2 * filter->sortbuf_allocated * sizeof (struct ucs4_with_ccc)); + memcpy (new_sortbuf, filter->sortbuf, + sortbuf_count * sizeof (struct ucs4_with_ccc)); + if (filter->sortbuf != filter->sortbuf_preallocated) + free (filter->sortbuf); + filter->sortbuf = new_sortbuf; + } + filter->sortbuf[sortbuf_count].code = uc; + filter->sortbuf[sortbuf_count].ccc = ccc; + sortbuf_count++; + } + + filter->sortbuf_count = sortbuf_count; + } + + return 0; +} + +/* Bring data buffered in the filter to its destination, the encapsulated + stream. + Return 0 if successful, or -1 with errno set upon failure. + Note! If after calling this function, additional characters are written + into the filter, the resulting character sequence in the encapsulated stream + will not necessarily be normalized. */ +int +uninorm_filter_flush (struct uninorm_filter *filter) +{ + /* Cache sortbuf and sortbuf_count in local register variables. */ + struct ucs4_with_ccc * const sortbuf = filter->sortbuf; + size_t sortbuf_count = filter->sortbuf_count; + size_t j; + + /* Apply the canonical ordering algorithm to the accumulated + sequence of characters. */ + if (sortbuf_count > 1) + gl_uninorm_decompose_merge_sort_inplace (sortbuf, sortbuf_count, + sortbuf + sortbuf_count); + + if (filter->composer != NULL) + { + /* Attempt to combine decomposed characters, as specified + in the Unicode Standard Annex #15 "Unicode Normalization + Forms". We need to check + 1. whether the first accumulated character is a + "starter" (i.e. has ccc = 0). This is usually the + case. But when the string starts with a + non-starter, the sortbuf also starts with a + non-starter. Btw, this check could also be + omitted, because the composition table has only + entries (code1, code2) for which code1 is a + starter; if the first accumulated character is not + a starter, no lookup will succeed. + 2. If the sortbuf has more than one character, check + for each of these characters that are not "blocked" + from the starter (i.e. have a ccc that is higher + than the ccc of the previous character) whether it + can be combined with the first character. + 3. If only one character is left in sortbuf, check + whether it can be combined with the next character + (also a starter). */ + if (sortbuf_count > 0 && sortbuf[0].ccc == 0) + { + for (j = 1; j < sortbuf_count; ) + { + if (sortbuf[j].ccc > sortbuf[j - 1].ccc) + { + ucs4_t combined = + filter->composer (sortbuf[0].code, sortbuf[j].code); + if (combined) + { + size_t k; + + sortbuf[0].code = combined; + /* sortbuf[0].ccc = 0, still valid. */ + for (k = j + 1; k < sortbuf_count; k++) + sortbuf[k - 1] = sortbuf[k]; + sortbuf_count--; + continue; + } + } + j++; + } + } + } + + for (j = 0; j < sortbuf_count; j++) + { + ucs4_t muc = sortbuf[j].code; + + /* Output muc to the encapsulated stream. */ + int ret = filter->stream_func (filter->stream_data, muc); + if (ret < 0) + { + /* errno is set here. */ + filter->sortbuf_count = 0; + return -1; + } + } + + /* sortbuf is now empty. */ + filter->sortbuf_count = 0; + + return 0; +} + +/* Bring data buffered in the filter to its destination, the encapsulated + stream, then close and free the filter. + Return 0 if successful, or -1 with errno set upon failure. */ +int +uninorm_filter_free (struct uninorm_filter *filter) +{ + int ret = uninorm_filter_flush (filter); + + if (ret < 0) + /* errno is set here. */ + return -1; + + if (filter->sortbuf_count > 0) + abort (); + if (filter->sortbuf != filter->sortbuf_preallocated) + free (filter->sortbuf); + free (filter); + + return 0; +}
new file mode 100644 --- /dev/null +++ b/modules/uninorm/filter @@ -0,0 +1,27 @@ +Description: +Normalization of a stream of Unicode characters. + +Files: +lib/uninorm/uninorm-filter.c +lib/uninorm/normalize-internal.h + +Depends-on: +uninorm/base +unictype/combining-class +uninorm/decompose-internal +malloc-posix + +configure.ac: + +Makefile.am: +lib_SOURCES += uninorm/uninorm-filter.c + +Include: +"uninorm.h" + +License: +LGPL + +Maintainer: +Bruno Haible +