/*------------------------------------------------------------------------------ * gms_lob.cpp * * gms_lob内置包的实现 * * Copyright (c) 2002-2012, PostgreSQL Global Development Group * Portions Copyright (c) 2021, openGauss Contributors * * IDENTIFICATION * contrib/gms_stats/gms_lob.cpp * *------------------------------------------------------------------------------ */ #include "postgres.h" #include "knl/knl_session.h" #include "utils/memutils.h" #include "catalog/pg_proc.h" #include "c.h" #include "miscadmin.h" #include "access/xact.h" #include "access/hash.h" #include "utils/rel.h" #include "utils/builtins.h" #include "utils/syscache.h" #include "access/genam.h" #include "utils/lsyscache.h" #include "executor/spi.h" #include "lib/stringinfo.h" #include "executor/executor.h" #include "catalog/storage_gtt.h" #include "utils/numeric.h" #include "access/tuptoaster.h" #include "funcapi.h" #include "fmgr.h" #include "catalog/pg_directory.h" #include "mb/pg_wchar.h" #include "libpq/pqformat.h" #include "storage/ipc.h" #include "utils/acl.h" #include "utils/bytea.h" #include "libpq/be-fsstubs.h" #include "libpq/libpq-fs.h" #include "commands/extension.h" #include "gms_lob.h" #include "utils/palloc.h" PG_MODULE_MAGIC; #define NUMLOB 64 static uint32 gmslob_index; PG_FUNCTION_INFO_V1(gms_lob_og_createtemporary); PG_FUNCTION_INFO_V1(gms_lob_og_freetemporary); PG_FUNCTION_INFO_V1(gms_lob_og_read_blob); PG_FUNCTION_INFO_V1(gms_lob_og_read_clob); PG_FUNCTION_INFO_V1(gms_lob_og_write_blob); PG_FUNCTION_INFO_V1(gms_lob_og_write_clob); PG_FUNCTION_INFO_V1(gms_lob_og_isopen); PG_FUNCTION_INFO_V1(gms_lob_og_open); PG_FUNCTION_INFO_V1(gms_lob_og_append_blob); PG_FUNCTION_INFO_V1(gms_lob_og_append_clob); PG_FUNCTION_INFO_V1(gms_lob_og_close); PG_FUNCTION_INFO_V1(gms_lob_og_cloblength); PG_FUNCTION_INFO_V1(gms_lob_og_bloblength); PG_FUNCTION_INFO_V1(gms_lob_og_null); void init_session_vars(void) { RepallocSessionVarsArrayIfNecessary(); GmsLobContext* psc = (GmsLobContext*)MemoryContextAllocZero(u_sess->self_mem_cxt, sizeof(GmsLobContext)); u_sess->attr.attr_common.extension_session_vars_array[gmslob_index] = psc; psc->gmsLobNameHash = NULL; } GmsLobContext* get_session_context() { if (u_sess->attr.attr_common.extension_session_vars_array[gmslob_index] == NULL) { init_session_vars(); } return (GmsLobContext*)u_sess->attr.attr_common.extension_session_vars_array[gmslob_index]; } static int32 getVarSize(varlena* var) { if (VARATT_IS_HUGE_TOAST_POINTER(var)) { struct varatt_lob_external large_toast_pointer; VARATT_EXTERNAL_GET_HUGE_POINTER(large_toast_pointer, var); return large_toast_pointer.va_rawsize; } else { return VARSIZE_ANY_EXHDR(var); } } /* * charlen_to_bytelen() * Compute the number of bytes occupied by n characters starting at *p * * It is caller's responsibility that there actually are n characters; * the string need not be null-terminated. */ static int charlen_to_bytelen(const char* p, int n) { if (pg_database_encoding_max_length() == 1) { /* Optimization for single-byte encodings */ return n; } else { const char* s = NULL; for (s = p; n > 0; n--) s += pg_mblen(s); return s - p; } } /* numeric 向下取整转成int4 */ int32 numericFloorToInt4(Numeric num) { Datum datumnum = DirectFunctionCall1(numeric_floor, NumericGetDatum(num)); return DatumGetInt32(DirectFunctionCall1(numeric_int4, datumnum)); } /***************************************************************************** * LOB哈希表相关 *****************************************************************************/ struct GmsLobHashKey { char* keyvalue; int length; }; typedef struct LobHashEnt { GmsLobHashKey key; /* hash表key值 */ int open_mode; /* 打开方式 */ } LobHashEnt; /* * lob数据的hash值生成函数 */ uint32 lob_hash(const void* key, Size kwysize) { const GmsLobHashKey* hash_key = (const GmsLobHashKey*)key; return DatumGetUInt32(hash_any((const unsigned char*)hash_key->keyvalue, hash_key->length)); } /* * lob数据的hash比较函数 */ int lob_match(const void* key1, const void* key2, Size kwysize) { const GmsLobHashKey* k1 = (const GmsLobHashKey*)key1; const GmsLobHashKey* k2 = (const GmsLobHashKey*)key2; if (k1->length > k2->length) { return 1; } else if (k1->length < k2->length) { return -1; } return strncmp(k1->keyvalue, k2->keyvalue, k1->length); } /* * 创建hash表 */ static HTAB* createlobHash() { HASHCTL hash_ctl; hash_ctl.keysize = sizeof(GmsLobHashKey); hash_ctl.entrysize = sizeof(LobHashEnt); hash_ctl.hash = lob_hash; hash_ctl.match = lob_match; return hash_create("Lob hash", NUMLOB, &hash_ctl, HASH_ELEM | HASH_FUNCTION | HASH_COMPARE); } /* * 程序退出时的清理函数 * 作为回调函数添加到proc_exit()调用的函数列表中 */ static void gms_lob_og_lob_exit(int code, Datum arg) { HASH_SEQ_STATUS scan; LobHashEnt *hentry = NULL; if (get_session_context()->gmsLobNameHash == NULL) { return; } hash_seq_init(&scan, get_session_context()->gmsLobNameHash); while ((hentry = (LobHashEnt *)hash_seq_search(&scan))) { if (hentry->key.keyvalue) { pfree(hentry->key.keyvalue); } } /* 清理hash表 */ hash_destroy(get_session_context()->gmsLobNameHash); get_session_context()->gmsLobNameHash = NULL; } char* generateLobKey(char* argname) { char* key = NULL; int keylen = 0; if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } TransactionId currentTransactionId = GetCurrentTransactionId(); // TransactionId采用16进制方式打印，逗号末尾结束符各占一个字节 keylen = strlen(argname) + sizeof(TransactionId) * 2 + 1 + 1; key = (char*)palloc0(keylen); errno_t errorno = snprintf_s(key, keylen, keylen - 1, "%16x,%s", currentTransactionId, argname); securec_check_ss(errorno, "\0", "\0"); return key; } int searchLob(char* argname, bool* found) { LobHashEnt* hentry = NULL; GmsLobHashKey hash_key; if (get_session_context()->gmsLobNameHash) { hash_key.keyvalue = generateLobKey(argname); hash_key.length = strlen(hash_key.keyvalue) + 1; hentry = (LobHashEnt*)hash_search(get_session_context()->gmsLobNameHash, &hash_key, HASH_FIND, NULL); if (hentry) { *found = true; return hentry->open_mode; } if (hash_key.keyvalue) { pfree(hash_key.keyvalue); } } else { get_session_context()->gmsLobNameHash = createlobHash(); on_proc_exit(&gms_lob_og_lob_exit, PointerGetDatum(NULL)); } *found = false; return -1; } static void closeLob(char* argname) { bool found; LobHashEnt* hentry = NULL; GmsLobHashKey hash_key; searchLob(argname, &found); if (found) { hash_key.keyvalue = generateLobKey(argname); hash_key.length = strlen(hash_key.keyvalue) + 1; hentry = (LobHashEnt*)hash_search(get_session_context()->gmsLobNameHash, &hash_key, HASH_REMOVE, NULL); if (!hentry) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("undefined lob."))); } if (hash_key.keyvalue) { pfree(hash_key.keyvalue); } if (hentry->key.keyvalue) { pfree(hentry->key.keyvalue); } } } static void openLob(char* argname, int openmode) { bool found; LobHashEnt* hentry = NULL; GmsLobHashKey hash_key; hash_key.keyvalue = generateLobKey(argname); hash_key.length = strlen(hash_key.keyvalue) + 1; hentry = (LobHashEnt*)hash_search(get_session_context()->gmsLobNameHash, &hash_key, HASH_ENTER, &found); if (found) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("duplicate lob(%s) openned", argname))); } hentry->key.keyvalue = (char*)MemoryContextAlloc(THREAD_GET_MEM_CXT_GROUP(MEMORY_CONTEXT_EXECUTOR), hash_key.length); int rc = memcpy_s(hentry->key.keyvalue, hash_key.length, hash_key.keyvalue, hash_key.length); securec_check(rc, "\0", "\0"); hentry->key.length = hash_key.length; hentry->open_mode = openmode; if (hash_key.keyvalue) { pfree(hash_key.keyvalue); } } /* * GMS_LOB.CREATETEMPORARY ( * lob_loc IN OUT BLOB/CLOB, --blob/clob对象 * cache IN BOOLEAN, --是否将LOB读取到缓冲区（不生效） * dur IN PLS_INTEGER := GMS_LOB.SESSION); --指定何时清除临时LOB（10/ SESSION：会话结束时；12/ CALL：调用结束时）(不生效 ) */ Datum gms_lob_og_createtemporary(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(3)); if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } varlena* res = NULL; if (PG_ARGISNULL(0)) { res = (varlena*)palloc(VARHDRSZ); SET_VARSIZE(res, VARHDRSZ); PG_RETURN_POINTER(res); } PG_RETURN_DATUM(PG_GETARG_DATUM(0)); } /* * GMS_LOB.FREETEMPORARY ( * lob_loc IN OUT BLOB/CLOB); --blob/clob对象 */ Datum gms_lob_og_freetemporary(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(1)); if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } /* lob如果没关闭，将其关闭 */ closeLob(argname); /* 返回一个空值的varlena */ varlena* res = (varlena*)palloc0(VARHDRSZ); SET_VARSIZE(res, VARHDRSZ); PG_RETURN_DATUM(PointerGetDatum(res)); } /* * lob_loc IN BLOB, * amount IN OUT NOCOPY BINARY_INTEGER, * offset IN INTEGER, * buffer INOUT RAW */ Datum gms_lob_og_read_blob(PG_FUNCTION_ARGS) { if (PG_ARGISNULL(0)) ereport(ERROR,(errcode(ERRCODE_INVALID_PARAMETER_VALUE),errmsg("invalid LOB object specified"))); if (PG_ARGISNULL(1) || PG_ARGISNULL(2)) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("numeric or value error"))); } bytea *src_lob = PG_GETARG_BYTEA_P(0); int32 amount = PG_GETARG_INT32(1); int32 offset = PG_GETARG_INT32(2); if (amount < 1 || amount > AMOUNT_MAX_SIZE) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("amount is invalid or out of range"))); } if (offset < 1 || offset > LOBMAXSIZE) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("offset is invalid or out of range"))); } int32 srclen = VARSIZE(src_lob) - VARHDRSZ; if (offset > srclen) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("no data found"))); } int32 srcamount = amount > (srclen - offset + 1) ? (srclen - offset + 1) : amount; //src实际复制的字节数 bytea* res = NULL; int rc = 0; res = (bytea*)palloc0(srcamount + VARHDRSZ); SET_VARSIZE(res, srcamount + VARHDRSZ); rc = memcpy_s(VARDATA(res), srcamount, VARDATA(src_lob) + offset - 1, srcamount); securec_check(rc, "\0", "\0"); TupleDesc tupdesc; Datum result; HeapTuple tuple; Datum values[2]; bool nulls[2] = { false, false }; /* 构造返回结果集 */ if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) { elog(ERROR, "return type must be a row type"); } /*拼接结果*/ values[0] = Int32GetDatum(srcamount); values[1] = PointerGetDatum(res); tuple = heap_form_tuple(tupdesc, values, nulls); result = HeapTupleGetDatum(tuple); PG_RETURN_DATUM(result); } /* * lob_loc IN CLOB, * amount IN OUT NOCOPY BINARY_INTEGER, * offset IN INTEGER, * buffer INOUT VARCHAR2 */ Datum gms_lob_og_read_clob(PG_FUNCTION_ARGS) { if (PG_ARGISNULL(0)) ereport(ERROR,(errcode(ERRCODE_INVALID_PARAMETER_VALUE),errmsg("invalid LOB object specified"))); if (PG_ARGISNULL(1) || PG_ARGISNULL(2)) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("numeric or value error"))); } text* src_lob = PG_GETARG_TEXT_P(0); int32 amount = PG_GETARG_INT32(1); int32 offset = PG_GETARG_INT32(2); if (amount < 1 || amount > AMOUNT_MAX_SIZE) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("amount is invalid or out of range"))); } if (offset < 1 || offset > LOBMAXSIZE) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("offset is invalid or out of range"))); } int32 srclen = DirectFunctionCall1(textlen, PointerGetDatum(src_lob)); if (offset > srclen) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("no data found"))); } int32 srcamount = amount > (srclen - offset + 1) ? (srclen - offset + 1) : amount; //src实际复制的字符数 int32 srcbytestart = charlen_to_bytelen(VARDATA(src_lob), offset - 1); //src复制起点 int32 copybyte = charlen_to_bytelen(VARDATA(src_lob) + srcbytestart, srcamount); //src实际复制的字节数 text* res = NULL; int rc = 0; res = (text*)palloc0(copybyte + VARHDRSZ); SET_VARSIZE(res, copybyte + VARHDRSZ); rc = memcpy_s(VARDATA(res), copybyte, VARDATA(src_lob) + srcbytestart, copybyte); securec_check(rc, "\0", "\0"); TupleDesc tupdesc; Datum result; HeapTuple tuple; Datum values[2]; bool nulls[2] = { false, false }; /* 构造返回结果集 */ if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) { elog(ERROR, "return type must be a row type"); } /*拼接结果*/ values[0] = Int32GetDatum(srcamount); values[1] = PointerGetDatum(res); tuple = heap_form_tuple(tupdesc, values, nulls); result = HeapTupleGetDatum(tuple); PG_RETURN_DATUM(result); } /* * GMS_LOB.WRITE ( * lob_loc IN OUT NOCOPY BLOB, --目标blob对象 * amount IN INTEGER, --指定的传入字节数 * offset IN INTEGER, --开始读取blob的字节数的偏移量（原点在1） * buffer IN RAW); --用于写的输入缓冲区 */ Datum gms_lob_og_write_blob(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(4)); /* check input args */ if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } if (PG_ARGISNULL(0)) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid LOB object specified"))); } if (PG_ARGISNULL(1) || PG_ARGISNULL(2)) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("Any of the input parameters are NULL"))); } bytea* destlob = PG_GETARG_BYTEA_P(0); int32 amount = numericFloorToInt4(PG_GETARG_NUMERIC(1)); int32 offset = numericFloorToInt4(PG_GETARG_NUMERIC(2)); bytea* buffer = PG_GETARG_BYTEA_P(3); int32 bufsize = getVarSize(buffer); if (amount < 1 || amount > 32767 || amount > bufsize) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("amount is invalid or out of range"))); } if (offset < 1 || offset > LOBMAXSIZE) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("Invalid argument value for dest_offset."))); } /* check lob's write and read permissions */ bool found; int32 openmode = searchLob(argname, &found); if (found && openmode == 0) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("cannot update a LOB opened in read-only mode."))); } int32 destlen = getVarSize(destlob); int destbytestart = (offset - 1) > destlen ? destlen : (offset - 1); int32 spacecnt = (offset - 1) > destlen ? (offset - destlen - 1) : 0; int32 appendbyte = amount; int32 destbyteend = (offset - 1 + appendbyte) > destlen ? destlen : (offset - 1 + appendbyte); int64 reslen = destbytestart + spacecnt + appendbyte + (destlen - destbyteend); bytea* res = NULL; char* resdata = NULL; int rc = 0; if (reslen != destlen || buffer == destlob) { /* dest is lack of space, or displaced copy when * buffer is the same as destlob, to avoid errors * in memcpy_s checking, reapply */ if (reslen > MAX_TOAST_CHUNK_SIZE - VARHDRSZ) { #ifdef ENABLE_MULTIPLE_NODES ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("Un-support clob/blob type more than 1GB for distributed system"))); #endif } res = (bytea*)palloc(reslen + VARHDRSZ); SET_VARSIZE(res, reslen + VARHDRSZ); } else { res = destlob; } resdata = VARDATA(res); if (destbytestart > 0 && res != destlob) { rc = memcpy_s(resdata, destbytestart, VARDATA(destlob), destbytestart); securec_check(rc, "\0", "\0"); } resdata += destbytestart; if (spacecnt > 0) { rc = memset_s(resdata, spacecnt, ' ', spacecnt); securec_check(rc, "\0", "\0"); } resdata += spacecnt; if (appendbyte > 0) { rc = memcpy_s(resdata, appendbyte, VARDATA(buffer), appendbyte); securec_check(rc, "\0", "\0"); } resdata += appendbyte; if (destbyteend < destlen && res != destlob) { rc = memcpy_s(resdata, destlen - destbyteend, VARDATA(destlob) + destbyteend, destlen - destbyteend); securec_check(rc, "\0", "\0"); } PG_RETURN_BYTEA_P(res); } /* * GMS_LOB.WRITE ( * lob_loc IN OUT NOCOPY CLOB CHARACTER SET ANY_CS, --目标clob对象 * amount IN INTEGER, --指定传入的字符数 * offset IN INTEGER, --开始读取blob的字符数的偏移量（原点在1） * buffer IN VARCHAR2 CHARACTER SET lob_loc%CHARSET); --用于写入的缓冲区 */ Datum gms_lob_og_write_clob(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(4)); /* check input args */ if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } if (PG_ARGISNULL(0)) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid LOB object specified"))); } if (PG_ARGISNULL(1) || PG_ARGISNULL(2)) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("Any of the input parameters are NULL"))); } text* destlob = PG_GETARG_TEXT_P(0); int32 amount = numericFloorToInt4(PG_GETARG_NUMERIC(1)); int32 offset = numericFloorToInt4(PG_GETARG_NUMERIC(2)); text* buffer = PG_GETARG_TEXT_P(3); int32 bufsize = DirectFunctionCall1(textlen, (Datum)buffer); if (amount < 1 || amount > 32767 || amount > bufsize) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("amount is invalid or out of range"))); } if (offset < 1 || offset > LOBMAXSIZE) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("Invalid argument value for dest_offset."))); } /* check lob's write and read permissions */ bool found; int32 openmode = searchLob(argname, &found); if (found && openmode == 0) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("cannot update a LOB opened in read-only mode."))); } int32 destlen = DirectFunctionCall1(textlen, (Datum)destlob); int32 srcamount = amount; int32 destbytestart = 0; int32 spacecnt = 0; int32 appendbyte = charlen_to_bytelen(VARDATA(buffer), srcamount); int32 destamount = 0; int32 destbyteend = 0; int32 destbytecnt = VARSIZE(destlob) - VARHDRSZ; int64 reslen = 0; text* res = NULL; char* resdata = NULL; int rc = 0; if (destlen < offset - 1) { destamount = destlen; spacecnt = offset - 1 - destamount; destbytestart = destbytecnt; destbyteend = destbytecnt; } else { destamount = srcamount > (destlen - offset + 1) ? (destlen - offset + 1) : srcamount; destbytestart = charlen_to_bytelen(VARDATA(destlob), offset - 1); destbyteend = charlen_to_bytelen(VARDATA(destlob) + destbytestart, destamount) + destbytestart; } reslen = destbytestart + spacecnt + appendbyte + (destbytecnt - destbyteend); if (reslen != destbytecnt || buffer == destlob) { /* dest is lack of space, or displaced copy when * buffer is the same as destlob, to avoid errors * in memcpy_s checking, reapply */ if (reslen > MAX_TOAST_CHUNK_SIZE - VARHDRSZ) { #ifdef ENABLE_MULTIPLE_NODES ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("Un-support clob/blob type more than 1GB for distributed system"))); #endif } res = (text*)palloc(reslen + VARHDRSZ); SET_VARSIZE(res, reslen + VARHDRSZ); } else { res = destlob; } resdata = VARDATA(res); if (destbytestart > 0 && res != destlob) { rc = memcpy_s(resdata, destbytestart, VARDATA(destlob), destbytestart); securec_check(rc, "\0", "\0"); } resdata += destbytestart; if (spacecnt > 0) { rc = memset_s(resdata, spacecnt, ' ', spacecnt); securec_check(rc, "\0", "\0"); } resdata += spacecnt; if (appendbyte > 0) { rc = memcpy_s(resdata, appendbyte, VARDATA(buffer), appendbyte); securec_check(rc, "\0", "\0"); } resdata += appendbyte; if (destbyteend < destbytecnt && res != destlob) { rc = memcpy_s(resdata, destbytecnt - destbyteend, VARDATA(destlob) + destbyteend, destbytecnt - destbyteend); securec_check(rc, "\0", "\0"); } PG_RETURN_TEXT_P(res); } /* * GMS_LOB.ISOPEN ( * lob_loc IN OUT BLOB/CLOB); --blob/clob对象 */ Datum gms_lob_og_isopen(PG_FUNCTION_ARGS) { bool found; char* argname = text_to_cstring(PG_GETARG_TEXT_P(1)); if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } searchLob(argname, &found); if (found) { PG_RETURN_UINT8(1); } else { PG_RETURN_UINT8(0); } } /* * GMS_LOB.OPEN ( * lob_loc IN OUT BLOB/CLOB, * open_mode IN BINARY_INTEGER); */ Datum gms_lob_og_open(PG_FUNCTION_ARGS) { if PG_ARGISNULL(0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid LOB object specified"))); } bool found; int openmode = PG_GETARG_INT32(1); if (openmode != 0 && openmode != 1) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid open_mode"))); } char* argname = text_to_cstring(PG_GETARG_TEXT_P(2)); if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } searchLob(argname, &found); if (found) { ereport(NOTICE, (errmsg("Lob(%s) already opened in the same transaction", argname))); PG_RETURN_DATUM(PG_GETARG_DATUM(0)); } openLob(argname, openmode); PG_RETURN_DATUM(PG_GETARG_DATUM(0)); } /* GMS_LOB.APPEND ( dest_lob IN OUT NOCOPY BLOB, --目标blob对象 src_lob IN BLOB); --源blob对象 */ Datum gms_lob_og_append_blob(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(2)); /* check input args */ if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } if (PG_ARGISNULL(0) || PG_ARGISNULL(1)) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid LOB object specified"))); } /* check lob's write and read permissions */ bool found; int32 openmode = searchLob(argname, &found); if (found && openmode == 0) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("cannot update a LOB opened in read-only mode."))); } Datum destlob = PG_GETARG_DATUM(0); Datum srclob = PG_GETARG_DATUM(1); Datum result = DirectFunctionCall2(byteacat, destlob, srclob); PG_RETURN_BYTEA_P(DatumGetPointer(result)); } /* GMS_LOB.APPEND ( dest_lob IN OUT NOCOPY CLOB CHARACTER SET ANY_CS, --目标clob对象 src_lob IN CLOB CHARACTER SET dest_lob%CHARSET); --源clob对象 */ Datum gms_lob_og_append_clob(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(2)); /* check input args */ if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } if (PG_ARGISNULL(0) || PG_ARGISNULL(1)) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid LOB object specified"))); } /* check lob's write and read permissions */ bool found; int32 openmode = searchLob(argname, &found); if (found && openmode == 0) { closeLob(argname); ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("cannot update a LOB opened in read-only mode."))); } Datum destlob = PG_GETARG_DATUM(0); Datum srclob = PG_GETARG_DATUM(1); Datum result = DirectFunctionCall2(textcat, destlob, srclob); PG_RETURN_TEXT_P(DatumGetPointer(result)); } /* * GMS_LOB.CLOSE ( * lob_loc IN OUT BLOB/CLOB); --blob/clob对象 */ Datum gms_lob_og_close(PG_FUNCTION_ARGS) { char* argname = text_to_cstring(PG_GETARG_TEXT_P(1)); if (strcmp(argname, ":") == 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("output parameter not a bind variable"))); } bool found; searchLob(argname, &found); if (!found) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("cannot perform operation on an unopened file or LOB"))); } closeLob(argname); PG_RETURN_DATUM(PG_GETARG_DATUM(0)); } /* * GMS_LOB.getlength ( * lob_loc IN OUT CLOB); --clob对象 */ Datum gms_lob_og_cloblength(PG_FUNCTION_ARGS) { Datum data = PG_GETARG_DATUM(0); int datalen = 0; datalen = DirectFunctionCall1(textlen, data); PG_RETURN_INT32(datalen); } /* * GMS_LOB.getlength ( * lob_loc IN OUT BLOB); --blob对象 */ Datum gms_lob_og_bloblength(PG_FUNCTION_ARGS) { bytea* data = PG_GETARG_BYTEA_P(0); int datalen = 0; datalen = VARSIZE(data) - VARHDRSZ; PG_RETURN_INT32(datalen); } /* * GMS_LOB.getlength (); --NULL对象 */ Datum gms_lob_og_null(PG_FUNCTION_ARGS) { PG_RETURN_VOID(); }