diff options
| -rw-r--r-- | doc/src/sgml/ref/psql-ref.sgml | 5 | ||||
| -rw-r--r-- | src/bin/psql/common.c | 132 |
2 files changed, 110 insertions, 27 deletions
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index 4e366944b60..8dce2924dbd 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.121 2004/08/24 00:06:51 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.122 2004/09/20 18:51:17 tgl Exp $ PostgreSQL documentation --> @@ -1875,7 +1875,8 @@ bar mode works by issuing an implicit <command>BEGIN</> for you, just before any command that is not already in a transaction block and is not itself a <command>BEGIN</> or other transaction-control - command. + command, nor a command that cannot be executed inside a transaction + block (such as <command>VACUUM</>). </para> <note> diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c index b3e0bbfb8d6..27b9a290fc5 100644 --- a/src/bin/psql/common.c +++ b/src/bin/psql/common.c @@ -3,7 +3,7 @@ * * Copyright (c) 2000-2004, PostgreSQL Global Development Group * - * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.90 2004/08/29 05:06:54 momjian Exp $ + * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.91 2004/09/20 18:51:19 tgl Exp $ */ #include "postgres_fe.h" #include "common.h" @@ -62,7 +62,7 @@ typedef struct _timeb TimevalStruct; extern bool prompt_state; -static bool is_transact_command(const char *query); +static bool command_no_begin(const char *query); /* @@ -895,7 +895,7 @@ SendQuery(const char *query) if (PQtransactionStatus(pset.db) == PQTRANS_IDLE && !GetVariableBool(pset.vars, "AUTOCOMMIT") && - !is_transact_command(query)) + !command_no_begin(query)) { results = PQexec(pset.db, "BEGIN"); if (PQresultStatus(results) != PGRES_COMMAND_OK) @@ -946,65 +946,147 @@ SendQuery(const char *query) return OK; } + /* - * check whether a query string begins with BEGIN/COMMIT/ROLLBACK/START XACT + * Advance the given char pointer over white space and SQL comments. */ -static bool -is_transact_command(const char *query) +static const char * +skip_white_space(const char *query) { - int wordlen; + int cnestlevel = 0; /* slash-star comment nest level */ - /* - * First we must advance over any whitespace and comments. - */ while (*query) { + int mblen = PQmblen(query, pset.encoding); + + /* + * Note: we assume the encoding is a superset of ASCII, so that + * for example "query[0] == '/'" is meaningful. However, we do NOT + * assume that the second and subsequent bytes of a multibyte + * character couldn't look like ASCII characters; so it is critical + * to advance by mblen, not 1, whenever we haven't exactly identified + * the character we are skipping over. + */ if (isspace((unsigned char) *query)) - query++; - else if (query[0] == '-' && query[1] == '-') + query += mblen; + else if (query[0] == '/' && query[1] == '*') { + cnestlevel++; query += 2; - while (*query && *query != '\n') - query++; } - else if (query[0] == '/' && query[1] == '*') + else if (cnestlevel > 0 && query[0] == '*' && query[1] == '/') + { + cnestlevel--; + query += 2; + } + else if (cnestlevel == 0 && query[0] == '-' && query[1] == '-') { query += 2; + /* + * We have to skip to end of line since any slash-star inside + * the -- comment does NOT start a slash-star comment. + */ while (*query) { - if (query[0] == '*' && query[1] == '/') + if (*query == '\n') { - query += 2; + query++; break; } - else - query++; + query += PQmblen(query, pset.encoding); } } + else if (cnestlevel > 0) + query += mblen; else break; /* found first token */ } + return query; +} + + +/* + * Check whether a command is one of those for which we should NOT start + * a new transaction block (ie, send a preceding BEGIN). + * + * These include the transaction control statements themselves, plus + * certain statements that the backend disallows inside transaction blocks. + */ +static bool +command_no_begin(const char *query) +{ + int wordlen; + /* - * Check word length ("beginx" is not "begin"). + * First we must advance over any whitespace and comments. + */ + query = skip_white_space(query); + + /* + * Check word length (since "beginx" is not "begin"). */ wordlen = 0; while (isalpha((unsigned char) query[wordlen])) - wordlen++; + wordlen += PQmblen(&query[wordlen], pset.encoding); + /* + * Transaction control commands. These should include every keyword + * that gives rise to a TransactionStmt in the backend grammar, except + * for the savepoint-related commands. + * + * (We assume that START must be START TRANSACTION, since there is + * presently no other "START foo" command.) + */ + if (wordlen == 5 && pg_strncasecmp(query, "abort", 5) == 0) + return true; if (wordlen == 5 && pg_strncasecmp(query, "begin", 5) == 0) return true; + if (wordlen == 5 && pg_strncasecmp(query, "start", 5) == 0) + return true; if (wordlen == 6 && pg_strncasecmp(query, "commit", 6) == 0) return true; - if (wordlen == 8 && pg_strncasecmp(query, "rollback", 8) == 0) + if (wordlen == 3 && pg_strncasecmp(query, "end", 3) == 0) return true; - if (wordlen == 5 && pg_strncasecmp(query, "abort", 5) == 0) + if (wordlen == 8 && pg_strncasecmp(query, "rollback", 8) == 0) return true; - if (wordlen == 3 && pg_strncasecmp(query, "end", 3) == 0) + + /* + * Commands not allowed within transactions. The statements checked + * for here should be exactly those that call PreventTransactionChain() + * in the backend. + * + * Note: we are a bit sloppy about CLUSTER, which is transactional in + * some variants but not others. + */ + if (wordlen == 6 && pg_strncasecmp(query, "vacuum", 6) == 0) return true; - if (wordlen == 5 && pg_strncasecmp(query, "start", 5) == 0) + if (wordlen == 7 && pg_strncasecmp(query, "cluster", 7) == 0) return true; + /* + * Note: these tests will match REINDEX TABLESPACE, which isn't really + * a valid command so we don't care much. The other five possible + * matches are correct. + */ + if ((wordlen == 6 && pg_strncasecmp(query, "create", 6) == 0) || + (wordlen == 4 && pg_strncasecmp(query, "drop", 4) == 0) || + (wordlen == 7 && pg_strncasecmp(query, "reindex", 7) == 0)) + { + query += wordlen; + + query = skip_white_space(query); + + wordlen = 0; + while (isalpha((unsigned char) query[wordlen])) + wordlen += PQmblen(&query[wordlen], pset.encoding); + + if (wordlen == 8 && pg_strncasecmp(query, "database", 8) == 0) + return true; + if (wordlen == 10 && pg_strncasecmp(query, "tablespace", 10) == 0) + return true; + } + return false; } |