diff options
Diffstat (limited to 'src/bin/pg_dump/pg_backup_archiver.h')
| -rw-r--r-- | src/bin/pg_dump/pg_backup_archiver.h | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h index 9d0f03d5629..2fdc0d341f3 100644 --- a/src/bin/pg_dump/pg_backup_archiver.h +++ b/src/bin/pg_dump/pg_backup_archiver.h @@ -253,15 +253,21 @@ struct _archiveHandle time_t createDate; /* Date archive created */ /* - * Fields used when discovering header. A format can always get the - * previous read bytes from here... + * Fields used when discovering archive format. For tar format, we load + * the first block into the lookahead buffer, and verify that it looks + * like a tar header. The tar module must then consume bytes from the + * lookahead buffer before reading any more from the file. For custom + * format, we load only the "PGDMP" marker into the buffer, and then set + * readHeader after confirming it matches. The buffer is vestigial in + * this case, as the subsequent code just checks readHeader and doesn't + * examine the buffer. */ - int readHeader; /* Used if file header has been read already */ + int readHeader; /* Set if we already read "PGDMP" marker */ char *lookahead; /* Buffer used when reading header to discover * format */ - size_t lookaheadSize; /* Size of allocated buffer */ - size_t lookaheadLen; /* Length of data in lookahead */ - pgoff_t lookaheadPos; /* Current read position in lookahead buffer */ + size_t lookaheadSize; /* Allocated size of buffer */ + size_t lookaheadLen; /* Length of valid data in lookahead */ + size_t lookaheadPos; /* Current read position in lookahead buffer */ ArchiveEntryPtrType ArchiveEntryPtr; /* Called for each metadata object */ StartDataPtrType StartDataPtr; /* Called when table data is about to be |