diff options
Diffstat (limited to 'src/backend/utils/mb/mbutils.c')
| -rw-r--r-- | src/backend/utils/mb/mbutils.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c index 86787bcb319..a8e13cacfde 100644 --- a/src/backend/utils/mb/mbutils.c +++ b/src/backend/utils/mb/mbutils.c @@ -68,6 +68,13 @@ static FmgrInfo *ToServerConvProc = NULL; static FmgrInfo *ToClientConvProc = NULL; /* + * This variable stores the conversion function to convert from UTF-8 + * to the server encoding. It's NULL if the server encoding *is* UTF-8, + * or if we lack a conversion function for this. + */ +static FmgrInfo *Utf8ToServerConvProc = NULL; + +/* * These variables track the currently-selected encodings. */ static const pg_enc2name *ClientEncoding = &pg_enc2name_tbl[PG_SQL_ASCII]; @@ -273,6 +280,8 @@ SetClientEncoding(int encoding) void InitializeClientEncoding(void) { + int current_server_encoding; + Assert(!backend_startup_complete); backend_startup_complete = true; @@ -289,6 +298,35 @@ InitializeClientEncoding(void) pg_enc2name_tbl[pending_client_encoding].name, GetDatabaseEncodingName()))); } + + /* + * Also look up the UTF8-to-server conversion function if needed. Since + * the server encoding is fixed within any one backend process, we don't + * have to do this more than once. + */ + current_server_encoding = GetDatabaseEncoding(); + if (current_server_encoding != PG_UTF8 && + current_server_encoding != PG_SQL_ASCII) + { + Oid utf8_to_server_proc; + + Assert(IsTransactionState()); + utf8_to_server_proc = + FindDefaultConversionProc(PG_UTF8, + current_server_encoding); + /* If there's no such conversion, just leave the pointer as NULL */ + if (OidIsValid(utf8_to_server_proc)) + { + FmgrInfo *finfo; + + finfo = (FmgrInfo *) MemoryContextAlloc(TopMemoryContext, + sizeof(FmgrInfo)); + fmgr_info_cxt(utf8_to_server_proc, finfo, + TopMemoryContext); + /* Set Utf8ToServerConvProc only after data is fully valid */ + Utf8ToServerConvProc = finfo; + } + } } /* @@ -752,6 +790,73 @@ perform_default_encoding_conversion(const char *src, int len, return result; } +/* + * Convert a single Unicode code point into a string in the server encoding. + * + * The code point given by "c" is converted and stored at *s, which must + * have at least MAX_UNICODE_EQUIVALENT_STRING+1 bytes available. + * The output will have a trailing '\0'. Throws error if the conversion + * cannot be performed. + * + * Note that this relies on having previously looked up any required + * conversion function. That's partly for speed but mostly because the parser + * may call this outside any transaction, or in an aborted transaction. + */ +void +pg_unicode_to_server(pg_wchar c, unsigned char *s) +{ + unsigned char c_as_utf8[MAX_MULTIBYTE_CHAR_LEN + 1]; + int c_as_utf8_len; + int server_encoding; + + /* + * Complain if invalid Unicode code point. The choice of errcode here is + * debatable, but really our caller should have checked this anyway. + */ + if (!is_valid_unicode_codepoint(c)) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("invalid Unicode code point"))); + + /* Otherwise, if it's in ASCII range, conversion is trivial */ + if (c <= 0x7F) + { + s[0] = (unsigned char) c; + s[1] = '\0'; + return; + } + + /* If the server encoding is UTF-8, we just need to reformat the code */ + server_encoding = GetDatabaseEncoding(); + if (server_encoding == PG_UTF8) + { + unicode_to_utf8(c, s); + s[pg_utf_mblen(s)] = '\0'; + return; + } + + /* For all other cases, we must have a conversion function available */ + if (Utf8ToServerConvProc == NULL) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("conversion between %s and %s is not supported", + pg_enc2name_tbl[PG_UTF8].name, + GetDatabaseEncodingName()))); + + /* Construct UTF-8 source string */ + unicode_to_utf8(c, c_as_utf8); + c_as_utf8_len = pg_utf_mblen(c_as_utf8); + c_as_utf8[c_as_utf8_len] = '\0'; + + /* Convert, or throw error if we can't */ + FunctionCall5(Utf8ToServerConvProc, + Int32GetDatum(PG_UTF8), + Int32GetDatum(server_encoding), + CStringGetDatum(c_as_utf8), + CStringGetDatum(s), + Int32GetDatum(c_as_utf8_len)); +} + /* convert a multibyte string to a wchar */ int |