diff options
Diffstat (limited to 'vendor/github.com/jackc/pgx/v5/pgproto3/pgproto3.go')
-rw-r--r-- | vendor/github.com/jackc/pgx/v5/pgproto3/pgproto3.go | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgx/v5/pgproto3/pgproto3.go b/vendor/github.com/jackc/pgx/v5/pgproto3/pgproto3.go new file mode 100644 index 0000000..128f97f --- /dev/null +++ b/vendor/github.com/jackc/pgx/v5/pgproto3/pgproto3.go @@ -0,0 +1,120 @@ +package pgproto3 + +import ( + "encoding/hex" + "errors" + "fmt" + + "github.com/jackc/pgx/v5/internal/pgio" +) + +// maxMessageBodyLen is the maximum length of a message body in bytes. See PG_LARGE_MESSAGE_LIMIT in the PostgreSQL +// source. It is defined as (MaxAllocSize - 1). MaxAllocSize is defined as 0x3fffffff. +const maxMessageBodyLen = (0x3fffffff - 1) + +// Message is the interface implemented by an object that can decode and encode +// a particular PostgreSQL message. +type Message interface { + // Decode is allowed and expected to retain a reference to data after + // returning (unlike encoding.BinaryUnmarshaler). + Decode(data []byte) error + + // Encode appends itself to dst and returns the new buffer. + Encode(dst []byte) ([]byte, error) +} + +// FrontendMessage is a message sent by the frontend (i.e. the client). +type FrontendMessage interface { + Message + Frontend() // no-op method to distinguish frontend from backend methods +} + +// BackendMessage is a message sent by the backend (i.e. the server). +type BackendMessage interface { + Message + Backend() // no-op method to distinguish frontend from backend methods +} + +type AuthenticationResponseMessage interface { + BackendMessage + AuthenticationResponse() // no-op method to distinguish authentication responses +} + +type invalidMessageLenErr struct { + messageType string + expectedLen int + actualLen int +} + +func (e *invalidMessageLenErr) Error() string { + return fmt.Sprintf("%s body must have length of %d, but it is %d", e.messageType, e.expectedLen, e.actualLen) +} + +type invalidMessageFormatErr struct { + messageType string + details string +} + +func (e *invalidMessageFormatErr) Error() string { + return fmt.Sprintf("%s body is invalid %s", e.messageType, e.details) +} + +type writeError struct { + err error + safeToRetry bool +} + +func (e *writeError) Error() string { + return fmt.Sprintf("write failed: %s", e.err.Error()) +} + +func (e *writeError) SafeToRetry() bool { + return e.safeToRetry +} + +func (e *writeError) Unwrap() error { + return e.err +} + +type ExceededMaxBodyLenErr struct { + MaxExpectedBodyLen int + ActualBodyLen int +} + +func (e *ExceededMaxBodyLenErr) Error() string { + return fmt.Sprintf("invalid body length: expected at most %d, but got %d", e.MaxExpectedBodyLen, e.ActualBodyLen) +} + +// getValueFromJSON gets the value from a protocol message representation in JSON. +func getValueFromJSON(v map[string]string) ([]byte, error) { + if v == nil { + return nil, nil + } + if text, ok := v["text"]; ok { + return []byte(text), nil + } + if binary, ok := v["binary"]; ok { + return hex.DecodeString(binary) + } + return nil, errors.New("unknown protocol representation") +} + +// beginMessage begins a new message of type t. It appends the message type and a placeholder for the message length to +// dst. It returns the new buffer and the position of the message length placeholder. +func beginMessage(dst []byte, t byte) ([]byte, int) { + dst = append(dst, t) + sp := len(dst) + dst = pgio.AppendInt32(dst, -1) + return dst, sp +} + +// finishMessage finishes a message that was started with beginMessage. It computes the message length and writes it to +// dst[sp]. If the message length is too large it returns an error. Otherwise it returns the final message buffer. +func finishMessage(dst []byte, sp int) ([]byte, error) { + messageBodyLen := len(dst[sp:]) + if messageBodyLen > maxMessageBodyLen { + return nil, errors.New("message body too large") + } + pgio.SetInt32(dst[sp:], int32(messageBodyLen)) + return dst, nil +} |