From: Ben Pfaff Date: Sun, 13 Feb 2011 18:43:57 +0000 (-0800) Subject: i18n: New functions for truncating strings in an arbitrary encoding. X-Git-Tag: v0.7.7~23 X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9d1d71e732eeed85ca3002b264e1269cdd005a3f;p=pspp-builds.git i18n: New functions for truncating strings in an arbitrary encoding. --- diff --git a/Smake b/Smake index 8c6669d0..7efa2cfb 100644 --- a/Smake +++ b/Smake @@ -73,6 +73,7 @@ GNULIB_MODULES = \ unistd \ unictype/property-id-continue \ unictype/property-id-start \ + unigbrk/uc-is-grapheme-break \ unistr/u8-cpy \ unistr/u8-mbtouc \ unistr/u8-strlen \ diff --git a/src/libpspp/i18n.c b/src/libpspp/i18n.c index 29148a0e..e2893f3c 100644 --- a/src/libpspp/i18n.c +++ b/src/libpspp/i18n.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "libpspp/assertion.h" #include "libpspp/hmapx.h" @@ -35,6 +36,7 @@ #include "libpspp/str.h" #include "libpspp/version.h" +#include "gl/c-strcase.h" #include "gl/localcharset.h" #include "gl/xalloc.h" #include "gl/relocatable.h" @@ -205,6 +207,279 @@ recode_string_pool (const char *to, const char *from, return out.string; } +/* Returns the name of the encoding that should be used for file names. + + This is meant to be the same encoding used by g_filename_from_uri() and + g_filename_to_uri() in GLib. */ +static const char * +filename_encoding (void) +{ +#if defined _WIN32 || defined __WIN32__ + return "UTF-8"; +#else + return locale_charset (); +#endif +} + +static char * +xconcat2 (const char *a, size_t a_len, + const char *b, size_t b_len) +{ + char *s = xmalloc (a_len + b_len + 1); + memcpy (s, a, a_len); + memcpy (s + a_len, b, b_len); + s[a_len + b_len] = '\0'; + return s; +} + +/* Conceptually, this function concatenates HEAD_LEN-byte string HEAD and + TAIL_LEN-byte string TAIL, both encoded in UTF-8, then converts them to + ENCODING. If the re-encoded result is no more than MAX_LEN bytes long, then + it returns HEAD_LEN. Otherwise, it drops one character[*] from the end of + HEAD and tries again, repeating as necessary until the concatenated result + fits or until HEAD_LEN reaches 0. + + [*] Actually this function drops grapheme clusters instead of characters, so + that, e.g. a Unicode character followed by a combining accent character + is either completely included or completely excluded from HEAD_LEN. See + UAX #29 at http://unicode.org/reports/tr29/ for more information on + grapheme clusters. + + A null ENCODING is treated as UTF-8. + + Sometimes this function has to actually construct the concatenated string to + measure its length. When this happens, it sets *RESULTP to that + null-terminated string, allocated with malloc(), for the caller to use if it + needs it. Otherwise, it sets *RESULTP to NULL. + + Simple examples for encoding="UTF-8", max_len=6: + + head="abc", tail="xyz" => 3 + head="abcd", tail="xyz" => 3 ("d" dropped). + head="abc", tail="uvwxyz" => 0 ("abc" dropped). + head="abc", tail="tuvwxyz" => 0 ("abc" dropped). + + Examples for encoding="ISO-8859-1", max_len=6: + + head="éèä", tail="xyz" => 6 + (each letter in head is only 1 byte in ISO-8859-1 even though they + each take 2 bytes in UTF-8 encoding) +*/ +static size_t +utf8_encoding_concat__ (const char *head, size_t head_len, + const char *tail, size_t tail_len, + const char *encoding, size_t max_len, + char **resultp) +{ + *resultp = NULL; + if (head_len == 0) + return 0; + else if (encoding == NULL || !c_strcasecmp (encoding, "UTF-8")) + { + if (head_len + tail_len <= max_len) + return head_len; + else if (tail_len >= max_len) + return 0; + else + { + size_t copy_len; + size_t prev; + size_t ofs; + int mblen; + + copy_len = 0; + for (ofs = u8_mbtouc (&prev, CHAR_CAST (const uint8_t *, head), + head_len); + ofs <= max_len - tail_len; + ofs += mblen) + { + ucs4_t next; + + mblen = u8_mbtouc (&next, + CHAR_CAST (const uint8_t *, head + ofs), + head_len - ofs); + if (uc_is_grapheme_break (prev, next)) + copy_len = ofs; + + prev = next; + } + + return copy_len; + } + } + else + { + char *result; + + result = (tail_len > 0 + ? xconcat2 (head, head_len, tail, tail_len) + : CONST_CAST (char *, head)); + if (recode_string_len (encoding, "UTF-8", result, + head_len + tail_len) <= max_len) + { + *resultp = result != head ? result : NULL; + return head_len; + } + else + { + bool correct_result = false; + size_t copy_len; + size_t prev; + size_t ofs; + int mblen; + + copy_len = 0; + for (ofs = u8_mbtouc (&prev, CHAR_CAST (const uint8_t *, head), + head_len); + ofs <= head_len; + ofs += mblen) + { + ucs4_t next; + + mblen = u8_mbtouc (&next, + CHAR_CAST (const uint8_t *, head + ofs), + head_len - ofs); + if (uc_is_grapheme_break (prev, next)) + { + if (result != head) + { + memcpy (result, head, ofs); + memcpy (result + ofs, tail, tail_len); + result[ofs + tail_len] = '\0'; + } + + if (recode_string_len (encoding, "UTF-8", result, + ofs + tail_len) <= max_len) + { + correct_result = true; + copy_len = ofs; + } + else + correct_result = false; + } + + prev = next; + } + + if (result != head) + { + if (correct_result) + *resultp = result; + else + free (result); + } + + return copy_len; + } + } +} + +/* Concatenates a prefix of HEAD with all of TAIL and returns the result as a + null-terminated string owned by the caller. HEAD, TAIL, and the returned + string are all encoded in UTF-8. As many characters[*] from the beginning + of HEAD are included as will fit within MAX_LEN bytes supposing that the + resulting string were to be re-encoded in ENCODING. All of TAIL is always + included, even if TAIL by itself is longer than MAX_LEN in ENCODING. + + [*] Actually this function drops grapheme clusters instead of characters, so + that, e.g. a Unicode character followed by a combining accent character + is either completely included or completely excluded from the returned + string. See UAX #29 at http://unicode.org/reports/tr29/ for more + information on grapheme clusters. + + A null ENCODING is treated as UTF-8. + + Simple examples for encoding="UTF-8", max_len=6: + + head="abc", tail="xyz" => "abcxyz" + head="abcd", tail="xyz" => "abcxyz" + head="abc", tail="uvwxyz" => "uvwxyz" + head="abc", tail="tuvwxyz" => "tuvwxyz" + + Examples for encoding="ISO-8859-1", max_len=6: + + head="éèä", tail="xyz" => "éèäxyz" + (each letter in HEAD is only 1 byte in ISO-8859-1 even though they + each take 2 bytes in UTF-8 encoding) +*/ +char * +utf8_encoding_concat (const char *head, const char *tail, + const char *encoding, size_t max_len) +{ + size_t tail_len = strlen (tail); + size_t prefix_len; + char *result; + + prefix_len = utf8_encoding_concat__ (head, strlen (head), tail, tail_len, + encoding, max_len, &result); + return (result != NULL + ? result + : xconcat2 (head, prefix_len, tail, tail_len)); +} + +/* Returns the length, in bytes, of the string that would be returned by + utf8_encoding_concat() if passed the same arguments, but the implementation + is often more efficient. */ +size_t +utf8_encoding_concat_len (const char *head, const char *tail, + const char *encoding, size_t max_len) +{ + size_t tail_len = strlen (tail); + size_t prefix_len; + char *result; + + prefix_len = utf8_encoding_concat__ (head, strlen (head), tail, tail_len, + encoding, max_len, &result); + free (result); + return prefix_len + tail_len; +} + +/* Returns an allocated, null-terminated string, owned by the caller, + containing as many characters[*] from the beginning of S that would fit + within MAX_LEN bytes if the returned string were to be re-encoded in + ENCODING. Both S and the returned string are encoded in UTF-8. + + [*] Actually this function drops grapheme clusters instead of characters, so + that, e.g. a Unicode character followed by a combining accent character + is either completely included or completely excluded from the returned + string. See UAX #29 at http://unicode.org/reports/tr29/ for more + information on grapheme clusters. + + A null ENCODING is treated as UTF-8. +*/ +char * +utf8_encoding_trunc (const char *s, const char *encoding, size_t max_len) +{ + return utf8_encoding_concat (s, "", encoding, max_len); +} + +/* Returns the length, in bytes, of the string that would be returned by + utf8_encoding_trunc() if passed the same arguments, but the implementation + is often more efficient. */ +size_t +utf8_encoding_trunc_len (const char *s, const char *encoding, size_t max_len) +{ + return utf8_encoding_concat_len (s, "", encoding, max_len); +} + +/* Returns FILENAME converted from UTF-8 to the filename encoding. + On Windows the filename encoding is UTF-8; elsewhere it is based on the + current locale. */ +char * +utf8_to_filename (const char *filename) +{ + return recode_string (filename_encoding (), "UTF-8", filename, -1); +} + +/* Returns FILENAME converted from the filename encoding to UTF-8. + On Windows the filename encoding is UTF-8; elsewhere it is based on the + current locale. */ +char * +filename_to_utf8 (const char *filename) +{ + return recode_string ("UTF-8", filename_encoding (), filename, -1); +} + /* Converts the string TEXT, which should be encoded in FROM-encoding, to a dynamically allocated string in TO-encoding. Any characters which cannot be converted will be represented by '?'. @@ -268,7 +543,6 @@ i18n_init (void) hmapx_init (&map); } - const char * get_default_encoding (void) { diff --git a/src/libpspp/i18n.h b/src/libpspp/i18n.h index 78a97378..55f747b3 100644 --- a/src/libpspp/i18n.h +++ b/src/libpspp/i18n.h @@ -44,6 +44,19 @@ struct substring recode_substring_pool (const char *to, const char *from, size_t recode_string_len (const char *to, const char *from, const char *text, int len); +char *utf8_encoding_trunc (const char *, const char *encoding, + size_t max_len); +size_t utf8_encoding_trunc_len (const char *, const char *encoding, + size_t max_len); + +char *utf8_encoding_concat (const char *head, const char *tail, + const char *encoding, size_t max_len); +size_t utf8_encoding_concat_len (const char *head, const char *tail, + const char *encoding, size_t max_len); + +char *utf8_to_filename (const char *filename); +char *filename_to_utf8 (const char *filename); + bool valid_encoding (const char *enc); char get_system_decimal (void); diff --git a/tests/libpspp/i18n-test.c b/tests/libpspp/i18n-test.c index 03b96f2e..b433756b 100644 --- a/tests/libpspp/i18n-test.c +++ b/tests/libpspp/i18n-test.c @@ -28,24 +28,61 @@ int main (int argc, char *argv[]) { - char *s; + i18n_init (); + + if (argc == 5 && !strcmp (argv[1], "recode")) + { + const char *from = argv[2]; + const char *to = argv[3]; + const char *string = argv[4]; + char *result = recode_string (to, from, string, -1); + puts (result); + assert (strlen (result) == recode_string_len (to, from, string, -1)); + free (result); + } + else if (argc == 6 && !strcmp (argv[1], "concat")) + { + const char *head = argv[2]; + const char *tail = argv[3]; + const char *encoding = argv[4]; + int max_len = atoi (argv[5]); + char *result; - if (argc != 4) + result = utf8_encoding_concat (head, tail, encoding, max_len); + puts (result); + + assert (strlen (result) + == utf8_encoding_concat_len (head, tail, encoding, max_len)); + + if (tail[0] == '\0') + { + char *result2 = utf8_encoding_trunc (head, encoding, max_len); + assert (!strcmp (result, result2)); + assert (strlen (result2) + == utf8_encoding_trunc_len (head, encoding, max_len)); + free (result2); + } + + free (result); + } + else { - fprintf (stderr, - "usage: %s FROM TO STRING\n" - "where FROM is the source encoding,\n" - " TO is the target encoding,\n" - " and STRING is the text to recode.\n", - argv[0]); + fprintf (stderr, "\ +usage: %s recode FROM TO STRING\n\ +where FROM is the source encoding,\n\ + TO is the target encoding,\n\ + and STRING is the text to recode.\n\ +\n\ +usage: %s concat HEAD TAIL ENCODING MAX_LEN\n\ +where HEAD is the first string to concatenate\n\ + TAIL is the second string to concatenate\n\ + ENCODING is the encoding in which to measure the result's length\n\ + MAX_LEN is the maximum length of the result in ENCODING.\n", + argv[0], argv[0]); return EXIT_FAILURE; } - i18n_init (); - s = recode_string (argv[2], argv[1], argv[3], -1); - puts (s); - assert (strlen (s) == recode_string_len (argv[2], argv[1], argv[3], -1)); - free (s); + i18n_done (); return 0; } diff --git a/tests/libpspp/i18n.at b/tests/libpspp/i18n.at index ed29a7d6..5444a78f 100644 --- a/tests/libpspp/i18n.at +++ b/tests/libpspp/i18n.at @@ -1,50 +1,111 @@ -AT_BANNER([i18n routines]) +AT_BANNER([i18n recoding]) -# CHECK_I18N([TITLE], [FROM-CODING], [TO-CODING], [FROM-TEXT], [TO-TEXT]) +m4_divert_push([PREPARE_TESTS]) +supports_encodings () { + case "$host" in + *-*-linux* | *-*-*-gnu*) + dnl GNU/Linux always has the encodings we want. We can't ask + dnl config.charset about them because it has a special case here + dnl too and won't tell us. + return 0 + ;; + *) + for encoding in "$@"; do + $SHELL $top_srcdir/gl/config.charset "$host" | grep '$2' || return 77 + done + ;; + esac +} +m4_divert_pop([PREPARE_TESTS]) + +# CHECK_I18N_RECODE([TITLE], [FROM-CODING], [TO-CODING], +# [FROM-TEXT], [TO-TEXT]) # # Converts FROM-TEXT from FROM-CODING to TO-CODING and checks that the result -# is TO-TEXT. The "printf" program is applied to both FROM-TEXT and TO-TEXT -# to allow for backslash-escapes. (Be aware that hex escapes are not portable; -# use octal escapes instead.) -m4_define([CHECK_I18N], +# is TO-TEXT. The "printf" program is applied to both FROM-TEXT and TO-TEXT to +# allow for backslash-escapes. (Hex escapes are not portable; use octal +# escapes instead.) +m4_define([CHECK_I18N_RECODE], [AT_SETUP([convert $1]) AT_KEYWORDS([i18n]) dnl Skip the test if this host doesn't know the source and target encodings. - AT_CHECK( - [case "$host" in - *-*-linux* | *-*-*-gnu*) - dnl GNU/Linux always has the encodings we want. We can't ask - dnl config.charset about them because it has a special case here - dnl too and won't tell us. - ;; - *) - $SHELL $top_srcdir/gl/config.charset "$host" | grep '$2' || exit 77 - $SHELL $top_srcdir/gl/config.charset "$host" | grep '$3' || exit 77 - ;; - esac - ], [0], [ignore]) - AT_CHECK_UNQUOTED([i18n-test '$2' '$3' `printf '$4'`], [0], [`printf '$5'` + AT_CHECK([supports_encodings '$2' '$3']) + AT_CHECK_UNQUOTED([i18n-test recode '$2' '$3' `printf '$4'`], [0], [`printf '$5'` ]) AT_CLEANUP]) -CHECK_I18N([reflexively], [ASCII], [ASCII], [abc], [abc]) -CHECK_I18N([without any change], [ASCII], [UTF-8], [abc], [abc]) +CHECK_I18N_RECODE([reflexively], [ASCII], [ASCII], [abc], [abc]) +CHECK_I18N_RECODE([without any change], [ASCII], [UTF-8], [abc], [abc]) -CHECK_I18N([from ISO-8859-1 to UTF-8], [ISO-8859-1], [UTF-8], - [\242], [\302\242]) -CHECK_I18N([from UTF-8 to ISO-8859-1], [UTF-8], [ISO-8859-1], - [\302\242], [\242]) +CHECK_I18N_RECODE([from ISO-8859-1 to UTF-8], [ISO-8859-1], [UTF-8], + [\242], [\302\242]) +CHECK_I18N_RECODE([from UTF-8 to ISO-8859-1], [UTF-8], [ISO-8859-1], + [\302\242], [\242]) # 0xc0 == 0300 is invalid in UTF-8 -CHECK_I18N([invalid UTF-8 to ISO-8859-1], [UTF-8], [ISO-8859-1], - [xy\300z], [xy?z]) +CHECK_I18N_RECODE([invalid UTF-8 to ISO-8859-1], [UTF-8], [ISO-8859-1], + [xy\300z], [xy?z]) # 0xc2 == 0302 is the first byte of a 2-byte UTF-8 sequence -CHECK_I18N([truncated UTF-8 to ISO-8559-1], [UTF-8], [ISO-8859-1], - [xy\302], [xy?]) +CHECK_I18N_RECODE([truncated UTF-8 to ISO-8559-1], [UTF-8], [ISO-8859-1], + [xy\302], [xy?]) dnl The input to this test is 7 bytes long and the expected output is 9 bytes. dnl So it should exercise the E2BIG case -CHECK_I18N([from ISO-8859-1 to UTF-8 with overflow], [ISO-8859-1], [UTF-8], - [Tsch\374\337!], [Tsch\303\274\303\237!]) +CHECK_I18N_RECODE([from ISO-8859-1 to UTF-8 with overflow], + [ISO-8859-1], [UTF-8], + [Tsch\374\337!], [Tsch\303\274\303\237!]) + +AT_BANNER([i18n concatenation]) + +# CHECK_I18N_CONCAT([HEAD], [TAIL], [ENCODING], [MAX-LEN], [ANSWER]) +# +# Concatenates HEAD and TAIL, omitting as many characters from HEAD as needed +# to make the result come out to no more than MAX-LEN bytes if it was expressed +# in ENCODING, and checks that the answer matches ANSWER. HEAD, TAIL, and +# ANSWER are all in UTF-8. The "printf" program is applied to HEAD, TAIL, and +# ANSWER to allow for backslash-escapes. (Hex escapes are not portable; use +# octal escapes instead.) +m4_define([CHECK_I18N_CONCAT], + [AT_SETUP([m4_if([$2], [], [truncate "$1" to $4 bytes in $3], + [truncate "$1" + "$2" to $4 bytes in $3])]) + AT_KEYWORDS([i18n]) + + dnl Skip the test if this host doesn't know the encoding. + AT_CHECK([supports_encodings '$3']) + AT_CHECK_UNQUOTED( + [i18n-test concat "`printf '$1'`" "`printf '$2'`" '$3' '$4'], [0], + [`printf '$5'` +]) + AT_CLEANUP]) + +CHECK_I18N_CONCAT([abc], [], [UTF-8], [6], [abc]) +CHECK_I18N_CONCAT([], [xyz], [UTF-8], [6], [xyz]) +CHECK_I18N_CONCAT([], [], [UTF-8], [6], []) +CHECK_I18N_CONCAT([abcdefghij], [], [UTF-8], [6], [abcdef]) +CHECK_I18N_CONCAT([], [tuvwxyz], [UTF-8], [6], [tuvwxyz]) + +CHECK_I18N_CONCAT([abc], [xyz], [UTF-8], [6], [abcxyz]) +CHECK_I18N_CONCAT([abcd], [xyz], [UTF-8], [6], [abcxyz]) +CHECK_I18N_CONCAT([abc], [uvwxyz], [UTF-8], [6], [uvwxyz]) + +# x in a box ( x⃞ ) is U+0078, U+20DE, 4 bytes in UTF-8, and one grapheme +# cluster. +CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [0], [y]) +CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [1], [y]) +CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [2], [y]) +CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [3], [y]) +CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [4], [y]) +CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [5], [x\342\203\236y]) +# éèä is only 3 bytes in ISO-8859-1. +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [0], [xyz]) +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [1], [xyz]) +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [2], [xyz]) +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [3], [xyz]) +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [4], + [\303\251xyz]) +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [5], + [\303\251\303\250xyz]) +CHECK_I18N_CONCAT([\303\251\303\250\303\244], [xyz], [ISO-8859-1], [6], + [\303\251\303\250\303\244xyz])