add catalog functions and execution support

- integrate Elastic/SQL REST endpoint for catalog functions;
- implement SQLGetTypeInfo, SQLTables, SQLColumns catalog functions;
- implement SQLPrepare, SQLExeute

- TODO: input SQL and parameter (of catalog fn's) escaping

driver/catalogue.c

@@ -4,6 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
+#include <stdio.h>
 #include <string.h>
 #include <wchar.h>
 
@@ -16,37 +17,14 @@
 #include "info.h"
 #include "queries.h"
 
-#define SQL_TABLES_TEXT		"SYS TABLES;"
-#define SQL_TABLES_JSON		"{\"table_pattern\" : \"" WPFWP_DESC "\"}"
-
-#define JSON_TABLES_PREFIX \
-	"{\"" JSON_ANSWER_COLUMNS "\": [" \
-		"{" \
-			"\"name\": \"TABLE_CAT\"," \
-			"\"type\": \"text\"" \
-		"}," \
-		"{" \
-			"\"name\": \"TABLE_SCHEM\"," \
-			"\"type\": \"text\"" \
-		"}," \
-		"{" \
-			"\"name\": \"TABLE_NAME\"," \
-			"\"type\": \"text\"" \
-		"}," \
-		"{" \
-			"\"name\": \"TABLE_TYPE\"," \
-			"\"type\": \"text\"" \
-		"}," \
-		"{" \
-			"\"name\": \"REMARKS\"," \
-			"\"type\": \"text\"" \
-		"}" \
-	"]," \
-	"\"" JSON_ANSWER_ROWS "\": ["
-#define JSON_TABLES_SUFFIX "]}"
-
-#define JSON_TABLES_ROW_TEMPLATE \
-	"[null,null,\"" LTPDL "\",\"TABLE\",\"\"]"
+#if 1
+#define SQL_TABLES_START	"SYS TABLES LIKE '"
+#define SQL_TABLES_END		"'"
+//#define SQL_TABLES_END		"';"
+#endif
+
+#define ESODBC_SQL_TABLES	"SYS TABLES LIKE"
+#define ESODBC_SQL_COLUMNS	"SYS COLUMNS TABLES LIKE"
 
 SQLRETURN EsSQLTablesW(
 		SQLHSTMT StatementHandle,
@@ -59,37 +37,29 @@ SQLRETURN EsSQLTablesW(
 		_In_reads_opt_(NameLength4) SQLTCHAR *TableType, 
 		SQLSMALLINT NameLength4)
 {
+	esodbc_stmt_st *stmt = STMH(StatementHandle);
 	SQLRETURN ret;
+	SQLTCHAR wbuf[ESODBC_MAX_IDENTIFIER_LEN + sizeof(SQL_TABLES_START) + 
+		sizeof(SQL_TABLES_END)]; /*includes 2x\0*/
 	SQLTCHAR *table_type, *table_name;
-	SQLTCHAR tbuf[SQL_MAX_IDENTIFIER_LEN + sizeof(SQL_TABLES_JSON)];
-	char u8[/*max bytes per character */4 * SQL_MAX_IDENTIFIER_LEN + 
-		sizeof(SQLTCHAR) * sizeof(SQL_TABLES_JSON)];
-	char *answer, faked[1<<16]; // FIXME: buffer handling
-	char *dupped;
-	esodbc_stmt_st *stmt = STMH(StatementHandle);
-	esodbc_dbc_st *dbc = stmt->dbc;
-	int i;
-	long count;
-	size_t len, pos;
-	UJObject obj, tables, table;
-	wchar_t *keys[] = {L"tables"};
-	const wchar_t *tname;
-	void *state = NULL, *iter;
+	size_t count, pos;
 
 	if (CatalogName && (wmemcmp(CatalogName, MK_TSTR(SQL_ALL_CATALOGS), 
 					NameLength1) != 0)) {
-		WARN("filtering by catalog is not supported."); /* TODO? */
+		ERR("filtering by catalog is not supported."); /* TODO? */
 		goto empty;
 	}
 	if (SchemaName && (wmemcmp(SchemaName, MK_TSTR(SQL_ALL_SCHEMAS), 
 					NameLength2) != 0)) {
-		WARN("filtering by schemas is not supported.");
+		ERR("filtering by schemas is not supported.");
 		goto empty;
 	}
-	if (TableType) {
+	if (TableType) { /* TODO: server support needed */
 		table_type = _wcsupr(TableType);
-		if (! wcsstr(table_type, MK_TSTR("TABLE"))) {
-			INFO("no 'TABLE' type fond in filter `"LTPD"`: empty result set");
+		if ((! wcsstr(table_type, MK_TSTR("TABLE"))) && 
+				(! wcsstr(table_type, MK_TSTR("ALIAS")))) {
+			WARN("no 'TABLE' or 'ALIAS' type fond in filter `"LTPD"`: "
+					"empty result set");
 			goto empty;
 		}
 	}
@@ -98,141 +68,114 @@ SQLRETURN EsSQLTablesW(
 		if (stmt->metadata_id == SQL_TRUE) {
 			// FIXME: string needs escaping of % \\ _
 			FIXME;
-		} else {
-			/* ES uses * as wildcard instead of % (TODO: only?) */
-			for (i = 0; i < NameLength3; i ++)
-				if (TableName[i] == (SQLTCHAR)'%')
-					TableName[i] = (SQLTCHAR)'*';
-			DBG("new table name after s/%%/*: `"LTPD"`.", TableName);
 		}
 		table_name = TableName;
+		count = NameLength3;
 	} else {
-		table_name = MK_TSTR("*");
+		table_name = MK_TSTR("%");
+		count = sizeof("%") - 1;
 	}
 
-	/* print JSON to send to server */
-	count = _snwprintf(tbuf, sizeof(tbuf), SQL_TABLES_JSON, table_name);
-	if ((count < 0) || sizeof(tbuf) <= count) {
-		ERRN("failed to print JSON or buffer too small (%d).", count);
-		RET_HDIAGS(stmt, SQL_STATE_HY000);
+	if (ESODBC_MAX_IDENTIFIER_LEN < NameLength3) {
+		ERR("TableName `" LTPDL "` too long (limit: %zd).", NameLength3,
+				TableName, ESODBC_MAX_IDENTIFIER_LEN);
+		RET_HDIAG(stmt, SQL_STATE_HY000, "TableName too long", 0);
 	}
+	/* print SQL to send to server */
+	/* count/pos always indicate number of characters (not bytes) */
+	pos = sizeof(SQL_TABLES_START) - 1;
+	memcpy(wbuf, MK_TSTR(SQL_TABLES_START), pos * sizeof(SQLTCHAR));
+	memcpy(&wbuf[pos], table_name, count * sizeof(SQLTCHAR));
+	pos += count;
+	count = sizeof(SQL_TABLES_END) - 1;
+	memcpy(&wbuf[pos], MK_TSTR(SQL_TABLES_END), count * sizeof(SQLTCHAR));
+	pos += count;
+
+	ret = EsSQLFreeStmt(stmt, ESODBC_SQL_CLOSE);
+	assert(SQL_SUCCEEDED(ret)); /* can't return error */
+	ret = attach_sql(stmt, wbuf, pos);
+	if (SQL_SUCCEEDED(ret))
+		ret = post_statement(stmt);
+	return ret;
 
-#ifdef _WIN32 /* TODO a Posix friendlier equivalent */
-	/* convert UCS2 -> UTF8
-	 * WC_NO_BEST_FIT_CHARS: https://docs.microsoft.com/en-us/sql/odbc/reference/develop-app/unicode-data
-	 */
-	count = WideCharToMultiByte(CP_UTF8, WC_NO_BEST_FIT_CHARS, tbuf, count, 
-			u8, sizeof(u8), NULL, NULL);
-	if (count <= 0) {
-		ERRN("conversion UCS2/UTF8 failed (%d).", count);
-		RET_HDIAGS(stmt, SQL_STATE_HY000);
-	} else {
-		DBG("UCS2/UTF8 converted on %d bytes.", count);
-	}
-#else /* _WIN32 */
-#	error "platform not supported"
-#endif /* _WIN32 */
-
-	/* attach the SQL textual statement to the handler */
-	ret = attach_sqltext(stmt, MK_TSTR(SQL_TABLES_TEXT),
-			sizeof(SQL_TABLES_TEXT)/*add 0-term*/);
-	if (! SQL_SUCCEEDED(ret))
-		return ret;
-
-#if 0
-	count = post_sql_tables(dbc, ESODBC_TIMEOUT_DEFAULT, u8, count, answer, 
-			sizeof(answer));
-	DBG("response received `%.*s` (%ld).", count, answer, count);
-#else //0
-	ret = post_sql_tables(stmt, ESODBC_TIMEOUT_DEFAULT, u8, count);
-	if (! SQL_SUCCEEDED(ret)) {
-		ERR("post failed.");
-		goto err;
-	}
-	answer = dbc->wbuf;
-	count = (long)dbc->wpos;
-	dbc->wbuf = NULL;
-	dbc->wlen = 0;
-	dbc->wpos = 0;
-	DBG("response received `%.*s` (%ld).", count, answer, count);
-#endif //0
-
-	/*
-	 * Note: UJDecode will treat UTF8 strings and UJReadString will return
-	 * directly wchar_t.
-	 */
-    obj = UJDecode(answer, count, NULL, &state);
-	free(answer);
-	answer = NULL;
-    if (UJObjectUnpack(obj, 1, "A", keys, &tables) < 1) {
-		ERR("failed to decode JSON answer: %s.", 
-				state ? UJGetError(state) : "<none>");
-		goto err;
-	}
-	DBG("unpacked array of size: %zd.", UJArraySize(tables));
+empty:
+	RET_HDIAG(stmt, SQL_STATE_HYC00, "Table filtering not supported", 0);
+}
 
-	assert(sizeof(JSON_TABLES_PREFIX) < sizeof(faked));
-	memcpy(faked, JSON_TABLES_PREFIX, sizeof(JSON_TABLES_PREFIX) - /*0term*/1);
-	pos = sizeof(JSON_TABLES_PREFIX) - 1;
-
-	iter = UJBeginArray(tables);
-	if (! iter) {
-		ERR("failed to obtain array iterator: %s.", UJGetError(state));
-		goto err;
+SQLRETURN EsSQLColumnsW
+(
+    SQLHSTMT           hstmt,
+    _In_reads_opt_(cchCatalogName) SQLWCHAR*    szCatalogName,
+    SQLSMALLINT        cchCatalogName,
+    _In_reads_opt_(cchSchemaName) SQLWCHAR*     szSchemaName,
+    SQLSMALLINT        cchSchemaName,
+    _In_reads_opt_(cchTableName) SQLWCHAR*      szTableName,
+    SQLSMALLINT        cchTableName,
+    _In_reads_opt_(cchColumnName) SQLWCHAR*     szColumnName,
+    SQLSMALLINT        cchColumnName
+)
+{
+	esodbc_stmt_st *stmt = STMH(hstmt);
+	SQLTCHAR *tablename, *columnname;
+	SQLSMALLINT tn_clen, cn_clen;
+	/* 8 for \' and spaces and extra */
+	SQLTCHAR wbuf[sizeof(ESODBC_SQL_COLUMNS) + 2 * ESODBC_MAX_IDENTIFIER_LEN + 8];
+	int clen;
+	SQLRETURN ret;
+
+	if (szCatalogName && (wmemcmp(szCatalogName, MK_TSTR(SQL_ALL_CATALOGS), 
+					cchCatalogName) != 0)) {
+		ERR("filtering by catalog is not supported."); /* TODO? */
+		goto empty;
 	}
-	count = 0;
-	while (UJIterArray(&iter, &table)) {
-		if (! UJIsString(table)) {
-			ERR("received non-string table name element (%d) - skipped.", 
-					UJGetType(table));
-			continue;
-		}
-		tname = UJReadString(table, &len);
-		DBG("available table: `" LTPDL "`.", len, tname);
-		count = snprintf(faked + pos, sizeof(faked), 
-				"%s" JSON_TABLES_ROW_TEMPLATE, count ? "," : "",
-				(int)len, tname);
-		if (count < 0) {
-			ERRN("buffer printing failed");
-			goto err;
-		} else if (count < sizeof(JSON_TABLES_ROW_TEMPLATE) - 1 
-				- sizeof(LTPDL) - 1 + len) {
-			ERR("buffer to small (%d) to print faked 'tables' JSON.", 
-					sizeof(faked));
-			goto err;
+	if (szSchemaName && (wmemcmp(szSchemaName, MK_TSTR(SQL_ALL_SCHEMAS), 
+					cchSchemaName) != 0)) {
+		ERR("filtering by schemas is not supported.");
+		goto empty;
+	}
+	if (szTableName && cchTableName) {
+		if (ESODBC_MAX_IDENTIFIER_LEN < cchTableName) {
+			ERR("TableName `" LTPDL "` too long (limit: %zd).", cchTableName,
+					szTableName, ESODBC_MAX_IDENTIFIER_LEN);
+			RET_HDIAG(stmt, SQL_STATE_HY000, "TableName too long", 0);
 		}
-		pos += count;
+		tablename = szTableName;
+		tn_clen = cchTableName;
+	} else {
+		tablename = MK_TSTR("%");
+		tn_clen = sizeof("%") - 1;
 	}
-    UJFree(state);
-	state = NULL;
-
-	if (sizeof(faked) <= pos + sizeof(JSON_TABLES_SUFFIX)/*w/ \0*/) {
-		ERR("buffer to small (%d) to print faked 'tables' JSON.", 
-				sizeof(faked));
-		goto err;
+	if (szColumnName && cchColumnName) {
+		if (ESODBC_MAX_IDENTIFIER_LEN < cchColumnName) {
+			ERR("ColumnName `" LTPDL "` too long (limit: %zd).", cchColumnName,
+					szColumnName, ESODBC_MAX_IDENTIFIER_LEN);
+			RET_HDIAG(stmt, SQL_STATE_HY000, "ColumnName too long", 0);
+		}
+		columnname = szColumnName;
+		cn_clen = cchColumnName;
+	} else {
+		columnname = MK_TSTR("%");
+		cn_clen = sizeof("%") - 1;
 	}
-	memcpy(faked + pos, JSON_TABLES_SUFFIX, sizeof(JSON_TABLES_SUFFIX));
-	pos += sizeof(JSON_TABLES_SUFFIX); /* includes \0 */
-
-	DBG("faked 'tables' answer: `%.*s`.", pos, faked);
 
-	dupped = (char *)malloc(pos);
-	if (! dupped) {
-		ERRN("failed to strndup faked answer.");
-		RET_HDIAGS(stmt, SQL_STATE_HY001);
+	clen = _snwprintf(wbuf, sizeof(wbuf)/sizeof(SQLTCHAR), 
+			MK_TSTR("%s '%.*s' '%.*s'"), MK_TSTR(ESODBC_SQL_COLUMNS), tn_clen,
+			tablename, cn_clen, columnname);
+	if (clen <= 0 || sizeof(wbuf)/sizeof(SQLTCHAR) <= clen) { /* == */
+		ERRN("SQL printing failed (buffer too small (%zdB)?).", sizeof(wbuf));
+		RET_HDIAGS(stmt, SQL_STATE_HY000);
 	}
-	memcpy(dupped, faked, pos);
-
-	return attach_answer(stmt, dupped, pos - /*\0*/1);
+
+	ret = EsSQLFreeStmt(stmt, ESODBC_SQL_CLOSE);
+	assert(SQL_SUCCEEDED(ret)); /* can't return error */
+	ret = attach_sql(stmt, wbuf, clen);
+	if (SQL_SUCCEEDED(ret))
+		ret = post_statement(stmt);
+	return ret;
 
 empty:
-	// FIXME: set empty result to statement
-	FIXME;
-	return SQL_SUCCESS;
-
-err:
-	// FIXME
-	if (state)
-		UJFree(state);
-	RET_HDIAGS(stmt, SQL_STATE_HY000);
+	RET_HDIAG(stmt, SQL_STATE_HYC00, "Table filtering not supported", 0);
 }
+
+
+/* vim: set noet fenc=utf-8 ff=dos sts=0 sw=4 ts=4 : */

driver/catalogue.h

@@ -20,6 +20,18 @@ SQLRETURN  EsSQLTablesW(
 		_In_reads_opt_(NameLength4) SQLWCHAR *TableType, 
 		SQLSMALLINT NameLength4);
 
+SQLRETURN EsSQLColumnsW
+(
+    SQLHSTMT           hstmt,
+    _In_reads_opt_(cchCatalogName) SQLWCHAR*    szCatalogName,
+    SQLSMALLINT        cchCatalogName,
+    _In_reads_opt_(cchSchemaName) SQLWCHAR*     szSchemaName,
+    SQLSMALLINT        cchSchemaName,
+    _In_reads_opt_(cchTableName) SQLWCHAR*      szTableName,
+    SQLSMALLINT        cchTableName,
+    _In_reads_opt_(cchColumnName) SQLWCHAR*     szColumnName,
+    SQLSMALLINT        cchColumnName
+);
 #endif /* __CATALOGUE_H__ */