add JS functions gzipCompress and gzipDecompress

modules/utils/script_builtins.go

@@ -1,6 +1,8 @@
 package utils
 
 import (
+	"bytes"
+	"compress/gzip"
 	"encoding/base64"
 	"io/ioutil"
 
@@ -157,6 +159,65 @@ func init() {
 		return v
 	}
 
+	// compress data with gzip
+	plugin.Defines["gzipCompress"] = func(call otto.FunctionCall) otto.Value {
+		argv := call.ArgumentList
+		argc := len(argv)
+		if argc != 1 {
+			return errOtto("gzipCompress: expected 1 argument, %d given instead.", argc)
+		}
+
+		uncompressed_bytes := []byte( argv[0].String() )
+
+		var writer_buffer bytes.Buffer
+		gzip_writer := gzip.NewWriter(&writer_buffer)
+		_, err := gzip_writer.Write(uncompressed_bytes)
+		if err != nil {
+			return errOtto( "gzipCompress: could not compress data: %s", err.Error() )
+		}
+		gzip_writer.Close()
+
+		compressed_bytes := writer_buffer.Bytes()
+
+		v, err := otto.ToValue( string(compressed_bytes) )
+		if err != nil {
+			return errOtto( "Could not convert to string: %s", err.Error() )
+		}
+
+		return v
+	}
+
+	// decompress data with gzip
+	plugin.Defines["gzipDecompress"] = func(call otto.FunctionCall) otto.Value {
+		argv := call.ArgumentList
+		argc := len(argv)
+		if argc != 1 {
+			return errOtto("gzipDecompress: expected 1 argument, %d given instead.", argc)
+		}
+
+		compressed_bytes := []byte( argv[0].String() )
+		reader_buffer := bytes.NewBuffer(compressed_bytes)
+
+		gzip_reader, err := gzip.NewReader(reader_buffer)
+		if err != nil {
+			return errOtto( "gzipDecompress: could not create gzip reader: %s", err.Error() )
+		}
+
+		var decompressed_buffer bytes.Buffer
+		_, err = decompressed_buffer.ReadFrom(gzip_reader)
+		if err != nil {
+			return errOtto( "gzipDecompress: could not decompress data: %s", err.Error() )
+		}
+
+		decompressed_bytes := decompressed_buffer.Bytes()
+		v, err := otto.ToValue( string(decompressed_bytes) )
+		if err != nil {
+			return errOtto( "Could not convert to string: %s", err.Error() )
+		}
+
+		return v
+	}
+
 	// read or write environment variable
 	plugin.Defines["env"] = func(call otto.FunctionCall) otto.Value {
 		argv := call.ArgumentList