From f3316a05b5ddee619ba0617716a4fef3ceb29ded Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 6 Jan 2012 13:04:09 -0500 Subject: [PATCH] Fix pg_restore's direct-to-database mode for INSERT-style table data. In commit 6545a901aaf84cb05212bb6a7674059908f527c3, I removed the mini SQL lexer that was in pg_backup_db.c, thinking that it had no real purpose beyond separating COPY data from SQL commands, which purpose had been obsoleted by long-ago fixes in pg_dump's archive file format. Unfortunately this was in error: that code was also used to identify command boundaries in INSERT-style table data, which is run together as a single string in the archive file for better compressibility. As a result, direct-to-database restores from archive files made with --inserts or --column-inserts fail in our latest releases, as reported by Dick Visser. To fix, restore the mini SQL lexer, but simplify it by adjusting the calling logic so that it's only required to cope with INSERT-style table data, not arbitrary SQL commands. This allows us to not have to deal with SQL comments, E'' strings, or dollar-quoted strings, none of which have ever been emitted by dumpTableData_insert. Also, fix the lexer to cope with standard-conforming strings, which was the actual bug that the previous patch was meant to solve. Back-patch to all supported branches. The previous patch went back to 8.2, which unfortunately means that the EOL release of 8.2 contains this bug, but I don't think we're doing another 8.2 release just because of that. --- src/bin/pg_dump/pg_backup_archiver.c | 23 ++++--- src/bin/pg_dump/pg_backup_archiver.h | 25 +++++++- src/bin/pg_dump/pg_backup_db.c | 90 +++++++++++++++++++++++++++- src/bin/pg_dump/pg_dump.c | 8 +++ 4 files changed, 135 insertions(+), 11 deletions(-) diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c index d9edebb0f4..234e50fb73 100644 --- a/src/bin/pg_dump/pg_backup_archiver.c +++ b/src/bin/pg_dump/pg_backup_archiver.c @@ -620,20 +620,20 @@ restore_toc_entry(ArchiveHandle *AH, TocEntry *te, if (te->copyStmt && strlen(te->copyStmt) > 0) { ahprintf(AH, "%s", te->copyStmt); - AH->writingCopyData = true; + AH->outputKind = OUTPUT_COPYDATA; } + else + AH->outputKind = OUTPUT_OTHERDATA; (*AH->PrintTocDataPtr) (AH, te, ropt); /* * Terminate COPY if needed. */ - if (AH->writingCopyData) - { - if (RestoringToDB(AH)) - EndDBCopyMode(AH, te); - AH->writingCopyData = false; - } + if (AH->outputKind == OUTPUT_COPYDATA && + RestoringToDB(AH)) + EndDBCopyMode(AH, te); + AH->outputKind = OUTPUT_SQLCMDS; /* close out the transaction started above */ if (is_parallel && te->created) @@ -1975,6 +1975,8 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt, AH->mode = mode; AH->compression = compression; + memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse)); + /* Open stdout with no compression for AH output handle */ AH->gzOut = 0; AH->OF = stdout; @@ -4194,7 +4196,8 @@ CloneArchive(ArchiveHandle *AH) clone = (ArchiveHandle *) pg_malloc(sizeof(ArchiveHandle)); memcpy(clone, AH, sizeof(ArchiveHandle)); - /* Handle format-independent fields ... none at the moment */ + /* Handle format-independent fields */ + memset(&(clone->sqlparse), 0, sizeof(clone->sqlparse)); /* The clone will have its own connection, so disregard connection state */ clone->connection = NULL; @@ -4227,7 +4230,9 @@ DeCloneArchive(ArchiveHandle *AH) /* Clear format-specific state */ (AH->DeClonePtr) (AH); - /* Clear state allocated by CloneArchive ... none at the moment */ + /* Clear state allocated by CloneArchive */ + if (AH->sqlparse.curCmd) + destroyPQExpBuffer(AH->sqlparse.curCmd); /* Clear any connection-local state */ if (AH->currUser) diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h index 7a4fd36073..6dd5158ab4 100644 --- a/src/bin/pg_dump/pg_backup_archiver.h +++ b/src/bin/pg_dump/pg_backup_archiver.h @@ -132,6 +132,20 @@ typedef void (*DeClonePtr) (struct _archiveHandle * AH); typedef size_t (*CustomOutPtr) (struct _archiveHandle * AH, const void *buf, size_t len); +typedef enum +{ + SQL_SCAN = 0, /* normal */ + SQL_IN_SINGLE_QUOTE, /* '...' literal */ + SQL_IN_DOUBLE_QUOTE /* "..." identifier */ +} sqlparseState; + +typedef struct +{ + sqlparseState state; /* see above */ + bool backSlash; /* next char is backslash quoted? */ + PQExpBuffer curCmd; /* incomplete line (NULL if not created) */ +} sqlparseInfo; + typedef enum { STAGE_NONE = 0, @@ -140,6 +154,13 @@ typedef enum STAGE_FINALIZING } ArchiverStage; +typedef enum +{ + OUTPUT_SQLCMDS = 0, /* emitting general SQL commands */ + OUTPUT_COPYDATA, /* writing COPY data */ + OUTPUT_OTHERDATA /* writing data as INSERT commands */ +} ArchiverOutput; + typedef enum { REQ_SCHEMA = 1, @@ -167,6 +188,8 @@ typedef struct _archiveHandle * Added V1.7 */ ArchiveFormat format; /* Archive format */ + sqlparseInfo sqlparse; /* state for parsing INSERT data */ + time_t createDate; /* Date archive created */ /* @@ -217,7 +240,7 @@ typedef struct _archiveHandle PGconn *connection; int connectToDB; /* Flag to indicate if direct DB connection is * required */ - bool writingCopyData; /* True when we are sending COPY data */ + ArchiverOutput outputKind; /* Flag for what we're currently writing */ bool pgCopyIn; /* Currently in libpq 'COPY IN' mode. */ int loFd; /* BLOB fd */ diff --git a/src/bin/pg_dump/pg_backup_db.c b/src/bin/pg_dump/pg_backup_db.c index bd1b8efac8..62c8b3356c 100644 --- a/src/bin/pg_dump/pg_backup_db.c +++ b/src/bin/pg_dump/pg_backup_db.c @@ -364,15 +364,93 @@ ExecuteSqlCommand(ArchiveHandle *AH, const char *qry, const char *desc) } +/* + * Process non-COPY table data (that is, INSERT commands). + * + * The commands have been run together as one long string for compressibility, + * and we are receiving them in bufferloads with arbitrary boundaries, so we + * have to locate command boundaries and save partial commands across calls. + * All state must be kept in AH->sqlparse, not in local variables of this + * routine. We assume that AH->sqlparse was filled with zeroes when created. + * + * We have to lex the data to the extent of identifying literals and quoted + * identifiers, so that we can recognize statement-terminating semicolons. + * We assume that INSERT data will not contain SQL comments, E'' literals, + * or dollar-quoted strings, so this is much simpler than a full SQL lexer. + */ +static void +ExecuteInsertCommands(ArchiveHandle *AH, const char *buf, size_t bufLen) +{ + const char *qry = buf; + const char *eos = buf + bufLen; + + /* initialize command buffer if first time through */ + if (AH->sqlparse.curCmd == NULL) + AH->sqlparse.curCmd = createPQExpBuffer(); + + for (; qry < eos; qry++) + { + char ch = *qry; + + /* For neatness, we skip any newlines between commands */ + if (!(ch == '\n' && AH->sqlparse.curCmd->len == 0)) + appendPQExpBufferChar(AH->sqlparse.curCmd, ch); + + switch (AH->sqlparse.state) + { + case SQL_SCAN: /* Default state == 0, set in _allocAH */ + if (ch == ';') + { + /* + * We've found the end of a statement. Send it and reset + * the buffer. + */ + ExecuteSqlCommand(AH, AH->sqlparse.curCmd->data, + "could not execute query"); + resetPQExpBuffer(AH->sqlparse.curCmd); + } + else if (ch == '\'') + { + AH->sqlparse.state = SQL_IN_SINGLE_QUOTE; + AH->sqlparse.backSlash = false; + } + else if (ch == '"') + { + AH->sqlparse.state = SQL_IN_DOUBLE_QUOTE; + } + break; + + case SQL_IN_SINGLE_QUOTE: + /* We needn't handle '' specially */ + if (ch == '\'' && !AH->sqlparse.backSlash) + AH->sqlparse.state = SQL_SCAN; + else if (ch == '\\' && !AH->public.std_strings) + AH->sqlparse.backSlash = !AH->sqlparse.backSlash; + else + AH->sqlparse.backSlash = false; + break; + + case SQL_IN_DOUBLE_QUOTE: + /* We needn't handle "" specially */ + if (ch == '"') + AH->sqlparse.state = SQL_SCAN; + break; + } + } +} + + /* * Implement ahwrite() for direct-to-DB restore */ int ExecuteSqlCommandBuf(ArchiveHandle *AH, const char *buf, size_t bufLen) { - if (AH->writingCopyData) + if (AH->outputKind == OUTPUT_COPYDATA) { /* + * COPY data. + * * We drop the data on the floor if libpq has failed to enter COPY * mode; this allows us to behave reasonably when trying to continue * after an error in a COPY command. @@ -382,9 +460,19 @@ ExecuteSqlCommandBuf(ArchiveHandle *AH, const char *buf, size_t bufLen) die_horribly(AH, modulename, "error returned by PQputCopyData: %s", PQerrorMessage(AH->connection)); } + else if (AH->outputKind == OUTPUT_OTHERDATA) + { + /* + * Table data expressed as INSERT commands. + */ + ExecuteInsertCommands(AH, buf, bufLen); + } else { /* + * General SQL commands; we assume that commands will not be split + * across calls. + * * In most cases the data passed to us will be a null-terminated * string, but if it's not, we have to add a trailing null. */ diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index 8db4071684..d1598ea4e9 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -1399,6 +1399,14 @@ dumpTableData_copy(Archive *fout, void *dcontext) return 1; } +/* + * Dump table data using INSERT commands. + * + * Caution: when we restore from an archive file direct to database, the + * INSERT commands emitted by this function have to be parsed by + * pg_backup_db.c's ExecuteInsertCommands(), which will not handle comments, + * E'' strings, or dollar-quoted strings. So don't emit anything like that. + */ static int dumpTableData_insert(Archive *fout, void *dcontext) {