diff options
Diffstat (limited to 'vendor/github.com/jackc/pgx/v5/large_objects.go')
| -rw-r--r-- | vendor/github.com/jackc/pgx/v5/large_objects.go | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgx/v5/large_objects.go b/vendor/github.com/jackc/pgx/v5/large_objects.go index c238ab9c2..676667450 100644 --- a/vendor/github.com/jackc/pgx/v5/large_objects.go +++ b/vendor/github.com/jackc/pgx/v5/large_objects.go @@ -67,6 +67,10 @@ type LargeObject struct { } // Write writes p to the large object and returns the number of bytes written and an error if not all of p was written. +// +// Write is implemented with a single call to lowrite. The PostgreSQL wire protocol has a limit of 1 GB - 1 per message. +// See definition of PQ_LARGE_MESSAGE_LIMIT in the PostgreSQL source code. To allow for the other data in the message, +// len(p) should be no larger than 1 GB - 1 KB. func (o *LargeObject) Write(p []byte) (int, error) { var n int err := o.tx.QueryRow(o.ctx, "select lowrite($1, $2)", o.fd, p).Scan(&n) @@ -82,6 +86,10 @@ func (o *LargeObject) Write(p []byte) (int, error) { } // Read reads up to len(p) bytes into p returning the number of bytes read. +// +// Read is implemented with a single call to loread. PostgreSQL internally allocates a single buffer for the response. +// The largest buffer PostgreSQL will allocate is 1 GB - 1. See definition of MaxAllocSize in the PostgreSQL source +// code. To allow for the other data in the message, len(p) should be no larger than 1 GB - 1 KB. func (o *LargeObject) Read(p []byte) (int, error) { var res []byte err := o.tx.QueryRow(o.ctx, "select loread($1, $2)", o.fd, len(p)).Scan(&res) |