diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/mb/mbutils.c | 205 |
1 files changed, 117 insertions, 88 deletions
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c index 08440e9fe9d..7f43cae69e2 100644 --- a/src/backend/utils/mb/mbutils.c +++ b/src/backend/utils/mb/mbutils.c @@ -1,10 +1,36 @@ -/* - * This file contains public functions for conversion between - * client encoding and server (database) encoding. +/*------------------------------------------------------------------------- + * + * mbutils.c + * This file contains functions for encoding conversion. + * + * The string-conversion functions in this file share some API quirks. + * Note the following: + * + * The functions return a palloc'd, null-terminated string if conversion + * is required. However, if no conversion is performed, the given source + * string pointer is returned as-is. + * + * Although the presence of a length argument means that callers can pass + * non-null-terminated strings, care is required because the same string + * will be passed back if no conversion occurs. Such callers *must* check + * whether result == src and handle that case differently. + * + * If the source and destination encodings are the same, the source string + * is returned without any verification; it's assumed to be valid data. + * If that might not be the case, the caller is responsible for validating + * the string using a separate call to pg_verify_mbstr(). Whenever the + * source and destination encodings are different, the functions ensure that + * the result is validly encoded according to the destination encoding. + * + * + * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California * - * Tatsuo Ishii * - * src/backend/utils/mb/mbutils.c + * IDENTIFICATION + * src/backend/utils/mb/mbutils.c + * + *------------------------------------------------------------------------- */ #include "postgres.h" @@ -290,7 +316,6 @@ InitializeClientEncoding(void) int pg_get_client_encoding(void) { - Assert(ClientEncoding); return ClientEncoding->encoding; } @@ -300,29 +325,13 @@ pg_get_client_encoding(void) const char * pg_get_client_encoding_name(void) { - Assert(ClientEncoding); return ClientEncoding->name; } /* - * Apply encoding conversion on src and return it. The encoding - * conversion function is chosen from the pg_conversion system catalog - * marked as "default". If it is not found in the schema search path, - * it's taken from pg_catalog schema. If it even is not in the schema, - * warn and return src. - * - * If conversion occurs, a palloc'd null-terminated string is returned. - * In the case of no conversion, src is returned. + * Convert src string to another encoding (general case). * - * CAUTION: although the presence of a length argument means that callers - * can pass non-null-terminated strings, care is required because the same - * string will be passed back if no conversion occurs. Such callers *must* - * check whether result == src and handle that case differently. - * - * Note: we try to avoid raising error, since that could get us into - * infinite recursion when this function is invoked during error message - * sending. It should be OK to raise error for overlength strings though, - * since the recursion will come with a shorter message. + * See the notes about string conversion functions at the top of this file. */ unsigned char * pg_do_encoding_conversion(unsigned char *src, int len, @@ -331,39 +340,32 @@ pg_do_encoding_conversion(unsigned char *src, int len, unsigned char *result; Oid proc; - if (!IsTransactionState()) - return src; + if (len <= 0) + return src; /* empty string is always valid */ if (src_encoding == dest_encoding) - return src; + return src; /* no conversion required, assume valid */ - if (src_encoding == PG_SQL_ASCII || dest_encoding == PG_SQL_ASCII) - return src; + if (dest_encoding == PG_SQL_ASCII) + return src; /* any string is valid in SQL_ASCII */ - if (len <= 0) + if (src_encoding == PG_SQL_ASCII) + { + /* No conversion is possible, but we must validate the result */ + (void) pg_verify_mbstr(dest_encoding, (const char *) src, len, false); return src; + } + + if (!IsTransactionState()) /* shouldn't happen */ + elog(ERROR, "cannot perform encoding conversion outside a transaction"); proc = FindDefaultConversionProc(src_encoding, dest_encoding); if (!OidIsValid(proc)) - { - ereport(LOG, + ereport(ERROR, (errcode(ERRCODE_UNDEFINED_FUNCTION), errmsg("default conversion function for encoding \"%s\" to \"%s\" does not exist", pg_encoding_to_char(src_encoding), pg_encoding_to_char(dest_encoding)))); - return src; - } - - /* - * XXX we should avoid throwing errors in OidFunctionCall. Otherwise we - * are going into infinite loop! So we have to make sure that the - * function exists before calling OidFunctionCall. - */ - if (!SearchSysCacheExists1(PROCOID, ObjectIdGetDatum(proc))) - { - elog(LOG, "cache lookup failed for function %u", proc); - return src; - } /* * Allocate space for conversion result, being wary of integer overflow @@ -387,7 +389,7 @@ pg_do_encoding_conversion(unsigned char *src, int len, } /* - * Convert string using encoding_name. The source + * Convert string to encoding encoding_name. The source * encoding is the DB encoding. * * BYTEA convert_to(TEXT string, NAME encoding_name) */ @@ -412,7 +414,7 @@ pg_convert_to(PG_FUNCTION_ARGS) } /* - * Convert string using encoding_name. The destination + * Convert string from encoding encoding_name. The destination * encoding is the DB encoding. * * TEXT convert_from(BYTEA string, NAME encoding_name) */ @@ -439,7 +441,7 @@ pg_convert_from(PG_FUNCTION_ARGS) } /* - * Convert string using encoding_names. + * Convert string between two arbitrary encodings. * * BYTEA convert(BYTEA string, NAME src_encoding_name, NAME dest_encoding_name) */ @@ -472,8 +474,13 @@ pg_convert(PG_FUNCTION_ARGS) src_str = VARDATA_ANY(string); pg_verify_mbstr_len(src_encoding, src_str, len, false); - dest_str = (char *) pg_do_encoding_conversion( - (unsigned char *) src_str, len, src_encoding, dest_encoding); + /* perform conversion */ + dest_str = (char *) pg_do_encoding_conversion((unsigned char *) src_str, + len, + src_encoding, + dest_encoding); + + /* update len if conversion actually happened */ if (dest_str != src_str) len = strlen(dest_str); @@ -503,10 +510,11 @@ pg_convert(PG_FUNCTION_ARGS) Datum length_in_encoding(PG_FUNCTION_ARGS) { - bytea *string = PG_GETARG_BYTEA_P(0); + bytea *string = PG_GETARG_BYTEA_PP(0); char *src_encoding_name = NameStr(*PG_GETARG_NAME(1)); int src_encoding = pg_char_to_encoding(src_encoding_name); - int len = VARSIZE(string) - VARHDRSZ; + const char *src_str; + int len; int retval; if (src_encoding < 0) @@ -515,11 +523,19 @@ length_in_encoding(PG_FUNCTION_ARGS) errmsg("invalid encoding name \"%s\"", src_encoding_name))); - retval = pg_verify_mbstr_len(src_encoding, VARDATA(string), len, false); - PG_RETURN_INT32(retval); + len = VARSIZE_ANY_EXHDR(string); + src_str = VARDATA_ANY(string); + + retval = pg_verify_mbstr_len(src_encoding, src_str, len, false); + PG_RETURN_INT32(retval); } +/* + * Get maximum multibyte character length in the specified encoding. + * + * Note encoding is specified numerically, not by name as above. + */ Datum pg_encoding_max_length_sql(PG_FUNCTION_ARGS) { @@ -532,27 +548,31 @@ pg_encoding_max_length_sql(PG_FUNCTION_ARGS) } /* - * convert client encoding to server encoding. + * Convert client encoding to server encoding. + * + * See the notes about string conversion functions at the top of this file. */ char * pg_client_to_server(const char *s, int len) { - Assert(ClientEncoding); - return pg_any_to_server(s, len, ClientEncoding->encoding); } /* - * convert any encoding to server encoding. + * Convert any encoding to server encoding. + * + * See the notes about string conversion functions at the top of this file. + * + * Unlike the other string conversion functions, this will apply validation + * even if encoding == DatabaseEncoding->encoding. This is because this is + * used to process data coming in from outside the database, and we never + * want to just assume validity. */ char * pg_any_to_server(const char *s, int len, int encoding) { - Assert(DatabaseEncoding); - Assert(ClientEncoding); - if (len <= 0) - return (char *) s; + return (char *) s; /* empty string is always valid */ if (encoding == DatabaseEncoding->encoding || encoding == PG_SQL_ASCII) @@ -594,46 +614,59 @@ pg_any_to_server(const char *s, int len, int encoding) return (char *) s; } - if (ClientEncoding->encoding == encoding) + /* Fast path if we can use cached conversion function */ + if (encoding == ClientEncoding->encoding) return perform_default_encoding_conversion(s, len, true); - else - return (char *) pg_do_encoding_conversion( - (unsigned char *) s, len, encoding, DatabaseEncoding->encoding); + + /* General case ... will not work outside transactions */ + return (char *) pg_do_encoding_conversion((unsigned char *) s, + len, + encoding, + DatabaseEncoding->encoding); } /* - * convert server encoding to client encoding. + * Convert server encoding to client encoding. + * + * See the notes about string conversion functions at the top of this file. */ char * pg_server_to_client(const char *s, int len) { - Assert(ClientEncoding); - return pg_server_to_any(s, len, ClientEncoding->encoding); } /* - * convert server encoding to any encoding. + * Convert server encoding to any encoding. + * + * See the notes about string conversion functions at the top of this file. */ char * pg_server_to_any(const char *s, int len, int encoding) { - Assert(DatabaseEncoding); - Assert(ClientEncoding); - if (len <= 0) - return (char *) s; + return (char *) s; /* empty string is always valid */ if (encoding == DatabaseEncoding->encoding || - encoding == PG_SQL_ASCII || - DatabaseEncoding->encoding == PG_SQL_ASCII) + encoding == PG_SQL_ASCII) return (char *) s; /* assume data is valid */ - if (ClientEncoding->encoding == encoding) + if (DatabaseEncoding->encoding == PG_SQL_ASCII) + { + /* No conversion is possible, but we must validate the result */ + (void) pg_verify_mbstr(encoding, s, len, false); + return (char *) s; + } + + /* Fast path if we can use cached conversion function */ + if (encoding == ClientEncoding->encoding) return perform_default_encoding_conversion(s, len, false); - else - return (char *) pg_do_encoding_conversion( - (unsigned char *) s, len, DatabaseEncoding->encoding, encoding); + + /* General case ... will not work outside transactions */ + return (char *) pg_do_encoding_conversion((unsigned char *) s, + len, + DatabaseEncoding->encoding, + encoding); } /* @@ -643,7 +676,8 @@ pg_server_to_any(const char *s, int len, int encoding) * SetClientEncoding(), no conversion is performed. */ static char * -perform_default_encoding_conversion(const char *src, int len, bool is_client_to_server) +perform_default_encoding_conversion(const char *src, int len, + bool is_client_to_server) { char *result; int src_encoding, @@ -931,11 +965,11 @@ raw_pg_bind_textdomain_codeset(const char *domainname, int encoding) * On most platforms, gettext defaults to the codeset implied by LC_CTYPE. * When that matches the database encoding, we don't need to do anything. In * CREATE DATABASE, we enforce or trust that the locale's codeset matches the - * database encoding, except for the C locale. (On Windows, we also permit a + * database encoding, except for the C locale. (On Windows, we also permit a * discrepancy under the UTF8 encoding.) For the C locale, explicitly bind * gettext to the right codeset. * - * On Windows, gettext defaults to the Windows ANSI code page. This is a + * On Windows, gettext defaults to the Windows ANSI code page. This is a * convenient departure for software that passes the strings to Windows ANSI * APIs, but we don't do that. Compel gettext to use database encoding or, * failing that, the LC_CTYPE encoding as it would on other platforms. @@ -980,28 +1014,24 @@ pg_bind_textdomain_codeset(const char *domainname) int GetDatabaseEncoding(void) { - Assert(DatabaseEncoding); return DatabaseEncoding->encoding; } const char * GetDatabaseEncodingName(void) { - Assert(DatabaseEncoding); return DatabaseEncoding->name; } Datum getdatabaseencoding(PG_FUNCTION_ARGS) { - Assert(DatabaseEncoding); return DirectFunctionCall1(namein, CStringGetDatum(DatabaseEncoding->name)); } Datum pg_client_encoding(PG_FUNCTION_ARGS) { - Assert(ClientEncoding); return DirectFunctionCall1(namein, CStringGetDatum(ClientEncoding->name)); } @@ -1014,7 +1044,6 @@ pg_client_encoding(PG_FUNCTION_ARGS) int GetMessageEncoding(void) { - Assert(MessageEncoding); return MessageEncoding->encoding; } |