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 | 161 |
1 files changed, 0 insertions, 161 deletions
diff --git a/vendor/github.com/jackc/pgx/v5/large_objects.go b/vendor/github.com/jackc/pgx/v5/large_objects.go deleted file mode 100644 index 9d21afdce..000000000 --- a/vendor/github.com/jackc/pgx/v5/large_objects.go +++ /dev/null @@ -1,161 +0,0 @@ -package pgx - -import ( - "context" - "errors" - "io" - - "github.com/jackc/pgx/v5/pgtype" -) - -// 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,maxLargeObjectMessageLength should be no larger than 1 GB - 1 KB. -var maxLargeObjectMessageLength = 1024*1024*1024 - 1024 - -// LargeObjects is a structure used to access the large objects API. It is only valid within the transaction where it -// was created. -// -// For more details see: http://www.postgresql.org/docs/current/static/largeobjects.html -type LargeObjects struct { - tx Tx -} - -type LargeObjectMode int32 - -const ( - LargeObjectModeWrite LargeObjectMode = 0x20000 - LargeObjectModeRead LargeObjectMode = 0x40000 -) - -// Create creates a new large object. If oid is zero, the server assigns an unused OID. -func (o *LargeObjects) Create(ctx context.Context, oid uint32) (uint32, error) { - err := o.tx.QueryRow(ctx, "select lo_create($1)", oid).Scan(&oid) - return oid, err -} - -// Open opens an existing large object with the given mode. ctx will also be used for all operations on the opened large -// object. -func (o *LargeObjects) Open(ctx context.Context, oid uint32, mode LargeObjectMode) (*LargeObject, error) { - var fd int32 - err := o.tx.QueryRow(ctx, "select lo_open($1, $2)", oid, mode).Scan(&fd) - if err != nil { - return nil, err - } - return &LargeObject{fd: fd, tx: o.tx, ctx: ctx}, nil -} - -// Unlink removes a large object from the database. -func (o *LargeObjects) Unlink(ctx context.Context, oid uint32) error { - var result int32 - err := o.tx.QueryRow(ctx, "select lo_unlink($1)", oid).Scan(&result) - if err != nil { - return err - } - - if result != 1 { - return errors.New("failed to remove large object") - } - - return nil -} - -// A LargeObject is a large object stored on the server. It is only valid within the transaction that it was initialized -// in. It uses the context it was initialized with for all operations. It implements these interfaces: -// -// io.Writer -// io.Reader -// io.Seeker -// io.Closer -type LargeObject struct { - ctx context.Context - tx Tx - fd int32 -} - -// Write writes p to the large object and returns the number of bytes written and an error if not all of p was written. -func (o *LargeObject) Write(p []byte) (int, error) { - nTotal := 0 - for { - expected := len(p) - nTotal - if expected == 0 { - break - } else if expected > maxLargeObjectMessageLength { - expected = maxLargeObjectMessageLength - } - - var n int - err := o.tx.QueryRow(o.ctx, "select lowrite($1, $2)", o.fd, p[nTotal:nTotal+expected]).Scan(&n) - if err != nil { - return nTotal, err - } - - if n < 0 { - return nTotal, errors.New("failed to write to large object") - } - - nTotal += n - - if n < expected { - return nTotal, errors.New("short write to large object") - } else if n > expected { - return nTotal, errors.New("invalid write to large object") - } - } - - return nTotal, nil -} - -// Read reads up to len(p) bytes into p returning the number of bytes read. -func (o *LargeObject) Read(p []byte) (int, error) { - nTotal := 0 - for { - expected := len(p) - nTotal - if expected == 0 { - break - } else if expected > maxLargeObjectMessageLength { - expected = maxLargeObjectMessageLength - } - - res := pgtype.PreallocBytes(p[nTotal:]) - err := o.tx.QueryRow(o.ctx, "select loread($1, $2)", o.fd, expected).Scan(&res) - // We compute expected so that it always fits into p, so it should never happen - // that PreallocBytes's ScanBytes had to allocate a new slice. - nTotal += len(res) - if err != nil { - return nTotal, err - } - - if len(res) < expected { - return nTotal, io.EOF - } else if len(res) > expected { - return nTotal, errors.New("invalid read of large object") - } - } - - return nTotal, nil -} - -// Seek moves the current location pointer to the new location specified by offset. -func (o *LargeObject) Seek(offset int64, whence int) (n int64, err error) { - err = o.tx.QueryRow(o.ctx, "select lo_lseek64($1, $2, $3)", o.fd, offset, whence).Scan(&n) - return n, err -} - -// Tell returns the current read or write location of the large object descriptor. -func (o *LargeObject) Tell() (n int64, err error) { - err = o.tx.QueryRow(o.ctx, "select lo_tell64($1)", o.fd).Scan(&n) - return n, err -} - -// Truncate the large object to size. -func (o *LargeObject) Truncate(size int64) (err error) { - _, err = o.tx.Exec(o.ctx, "select lo_truncate64($1, $2)", o.fd, size) - return err -} - -// Close the large object descriptor. -func (o *LargeObject) Close() error { - _, err := o.tx.Exec(o.ctx, "select lo_close($1)", o.fd) - return err -} |