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authorTom Lane2009-08-04 21:56:09 +0000
committerTom Lane2009-08-04 21:56:09 +0000
commitd885cf42f21f72245651f46849c9b97c4601cd2f (patch)
treeed12af61f36cf3910ed64189e7d1cf82464378b0
parent04ec2b3eab44225529781b05d1a63696b7cc214e (diff)
Fix pg_dump to do the right thing when escaping the contents of large objects.
The previous implementation got it right in most cases but failed in one: if you pg_dump into an archive with standard_conforming_strings enabled, then pg_restore to a script file (not directly to a database), the script will set standard_conforming_strings = on but then emit large object data as nonstandardly-escaped strings. At the moment the code is made to emit hex-format bytea strings when dumping to a script file. We might want to change to old-style escaping for backwards compatibility, but that would be slower and bulkier. If we do, it's just a matter of reimplementing appendByteaLiteral(). This has been broken for a long time, but given the lack of field complaints I'm not going to worry about back-patching.
-rw-r--r--src/bin/pg_dump/dumputils.c49
-rw-r--r--src/bin/pg_dump/dumputils.h3
-rw-r--r--src/bin/pg_dump/pg_backup_archiver.c15
-rw-r--r--src/bin/pg_dump/pg_backup_archiver.h3
-rw-r--r--src/bin/pg_dump/pg_backup_null.c15
5 files changed, 70 insertions, 15 deletions
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 178eb7c8d5..5a3f9c34ce 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -326,6 +326,55 @@ appendStringLiteralDQ(PQExpBuffer buf, const char *str, const char *dqprefix)
/*
+ * Convert a bytea value (presented as raw bytes) to an SQL string literal
+ * and append it to the given buffer. We assume the specified
+ * standard_conforming_strings setting.
+ *
+ * This is needed in situations where we do not have a PGconn available.
+ * Where we do, PQescapeByteaConn is a better choice.
+ */
+void
+appendByteaLiteral(PQExpBuffer buf, const unsigned char *str, size_t length,
+ bool std_strings)
+{
+ const unsigned char *source = str;
+ char *target;
+
+ static const char hextbl[] = "0123456789abcdef";
+
+ /*
+ * This implementation is hard-wired to produce hex-format output.
+ * We do not know the server version the output will be loaded into,
+ * so making an intelligent format choice is impossible. It might be
+ * better to always use the old escaped format.
+ */
+ if (!enlargePQExpBuffer(buf, 2 * length + 5))
+ return;
+
+ target = buf->data + buf->len;
+ *target++ = '\'';
+ if (!std_strings)
+ *target++ = '\\';
+ *target++ = '\\';
+ *target++ = 'x';
+
+ while (length-- > 0)
+ {
+ unsigned char c = *source++;
+
+ *target++ = hextbl[(c >> 4) & 0xF];
+ *target++ = hextbl[c & 0xF];
+ }
+
+ /* Write the terminating quote and NUL character. */
+ *target++ = '\'';
+ *target = '\0';
+
+ buf->len = target - buf->data;
+}
+
+
+/*
* Convert backend's version string into a number.
*/
int
diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index f493a41576..f693922cf4 100644
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -27,6 +27,9 @@ extern void appendStringLiteralConn(PQExpBuffer buf, const char *str,
PGconn *conn);
extern void appendStringLiteralDQ(PQExpBuffer buf, const char *str,
const char *dqprefix);
+extern void appendByteaLiteral(PQExpBuffer buf,
+ const unsigned char *str, size_t length,
+ bool std_strings);
extern int parse_version(const char *versionString);
extern bool parsePGArray(const char *atext, char ***itemarray, int *nitems);
extern bool buildACLCommands(const char *name, const char *subname,
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index fe4841a94e..012fb936b7 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -1249,20 +1249,19 @@ dump_lo_buf(ArchiveHandle *AH)
}
else
{
- unsigned char *str;
- size_t len;
+ PQExpBuffer buf = createPQExpBuffer();
- str = PQescapeBytea((const unsigned char *) AH->lo_buf,
- AH->lo_buf_used, &len);
- if (!str)
- die_horribly(AH, modulename, "out of memory\n");
+ appendByteaLiteralAHX(buf,
+ (const unsigned char *) AH->lo_buf,
+ AH->lo_buf_used,
+ AH);
/* Hack: turn off writingBlob so ahwrite doesn't recurse to here */
AH->writingBlob = 0;
- ahprintf(AH, "SELECT pg_catalog.lowrite(0, '%s');\n", str);
+ ahprintf(AH, "SELECT pg_catalog.lowrite(0, %s);\n", buf->data);
AH->writingBlob = 1;
- free(str);
+ destroyPQExpBuffer(buf);
}
AH->lo_buf_used = 0;
}
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 5c779bdcef..21ba8c031d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -342,6 +342,9 @@ extern bool checkSeek(FILE *fp);
#define appendStringLiteralAHX(buf,str,AH) \
appendStringLiteral(buf, str, (AH)->public.encoding, (AH)->public.std_strings)
+#define appendByteaLiteralAHX(buf,str,len,AH) \
+ appendByteaLiteral(buf, str, len, (AH)->public.std_strings)
+
/*
* Mandatory routines for each supported format
*/
diff --git a/src/bin/pg_dump/pg_backup_null.c b/src/bin/pg_dump/pg_backup_null.c
index 2ae7351cc1..fc48f1ba8d 100644
--- a/src/bin/pg_dump/pg_backup_null.c
+++ b/src/bin/pg_dump/pg_backup_null.c
@@ -23,6 +23,7 @@
*/
#include "pg_backup_archiver.h"
+#include "dumputils.h"
#include <unistd.h> /* for dup */
@@ -101,16 +102,16 @@ _WriteBlobData(ArchiveHandle *AH, const void *data, size_t dLen)
{
if (dLen > 0)
{
- unsigned char *str;
- size_t len;
+ PQExpBuffer buf = createPQExpBuffer();
- str = PQescapeBytea((const unsigned char *) data, dLen, &len);
- if (!str)
- die_horribly(AH, NULL, "out of memory\n");
+ appendByteaLiteralAHX(buf,
+ (const unsigned char *) data,
+ dLen,
+ AH);
- ahprintf(AH, "SELECT pg_catalog.lowrite(0, '%s');\n", str);
+ ahprintf(AH, "SELECT pg_catalog.lowrite(0, %s);\n", buf->data);
- free(str);
+ destroyPQExpBuffer(buf);
}
return dLen;
}