rename file so git tracking is better

internal/irzstd/writer.go

@@ -0,0 +1,112 @@
+// Package implements writer that converts log events to Zstd compressed IR. Effectively chaining
+// together [ir.Writer] and [zstd.Encoder] in series.
+
+package irzstd
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/klauspost/compress/zstd"
+
+	"github.com/y-scope/clp-ffi-go/ffi"
+	"github.com/y-scope/clp-ffi-go/ir"
+)
+
+type Writer interface {
+	// Converts log events to Zstd compressed IR and outputs to the Zstd buffer.
+	//
+	// Parameters:
+	//   - logEvents: A slice of log events to be encoded
+	//
+	// Returns:
+	//   - err
+	WriteIrZstd([]ffi.LogEvent) error
+
+	// Closes IR stream and Zstd frame. After calling close, Writer must be Reset() prior to calling
+	// write.
+	//
+	// Returns:
+	//   - err
+	CloseStreams() error
+
+	// Closes Writer.
+	//
+	// Returns:
+	//   - err
+	Close() error
+
+	// Reinitialize Writer after calling CloseStreams().
+	//
+	// Returns:
+	//   - err
+	Reset() error
+
+	// Getter for useDiskBuffer.
+	//
+	// Returns:
+	//   - useDiskBuffer: On/off for disk buffering
+	GetUseDiskBuffer() bool
+
+	// Getter for Zstd Output.
+	//
+	// Returns:
+	//   - zstdOutput: Reader for Zstd output
+	GetZstdOutput() io.Reader
+
+	// Get size of Zstd output.
+	//
+	// Returns:
+	//	 - size: Bytes written
+	//   - err
+	GetZstdOutputSize() (int, error)
+}
+
+// Writes log events to a IR Writer.
+//
+// Parameters:
+//   - irWriter: CLP IR writer to write each log event with
+//   - logEvents: A slice of log events to be encoded
+//
+// Returns:
+//   - err: error if an event could not be written
+func writeIr(irWriter *ir.Writer, logEvents []ffi.LogEvent) error {
+	for _, event := range logEvents {
+		_, err := irWriter.Write(event)
+		if err != nil {
+			err = fmt.Errorf("failed to encode event %v into ir: %w", event, err)
+			return err
+		}
+	}
+	return nil
+}
+
+// Opens a new [ir.Writer] and [zstd.Encoder].
+//
+// Parameters:
+//   - zstdOutput: Output location for Zstd
+//   - timezone: Time zone of the log source
+//   - size: Byte length
+//
+// Returns:
+//   - irWriter: Writer for CLP IR
+//   - ZstdWriter: Writer for Zstd
+//   - err: Error opening IR/Zstd writer
+func newIrZstdWriters(
+	zstdOutput io.Writer,
+	timezone string,
+	size int,
+) (*ir.Writer, *zstd.Encoder, error) {
+	// IR buffer using bytes.Buffer internally, so it will dynamically grow if undersized. Using
+	// FourByteEncoding as default encoding.
+	irWriter, err := ir.NewWriterSize[ir.FourByteEncoding](size, timezone)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error opening IR writer: %w", err)
+	}
+
+	zstdWriter, err := zstd.NewWriter(zstdOutput)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error opening Zstd writer: %w", err)
+	}
+	return irWriter, zstdWriter, err
+}