Add missing imports

vendor/github.com/technoweenie/multipartstreamer/multipartstreamer.go

@@ -0,0 +1,101 @@
+/*
+Package multipartstreamer helps you encode large files in MIME multipart format
+without reading the entire content into memory.  It uses io.MultiReader to
+combine an inner multipart.Reader with a file handle.
+*/
+package multipartstreamer
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime/multipart"
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+type MultipartStreamer struct {
+	ContentType   string
+	bodyBuffer    *bytes.Buffer
+	bodyWriter    *multipart.Writer
+	closeBuffer   *bytes.Buffer
+	reader        io.Reader
+	contentLength int64
+}
+
+// New initializes a new MultipartStreamer.
+func New() (m *MultipartStreamer) {
+	m = &MultipartStreamer{bodyBuffer: new(bytes.Buffer)}
+
+	m.bodyWriter = multipart.NewWriter(m.bodyBuffer)
+	boundary := m.bodyWriter.Boundary()
+	m.ContentType = "multipart/form-data; boundary=" + boundary
+
+	closeBoundary := fmt.Sprintf("\r\n--%s--\r\n", boundary)
+	m.closeBuffer = bytes.NewBufferString(closeBoundary)
+
+	return
+}
+
+// WriteFields writes multiple form fields to the multipart.Writer.
+func (m *MultipartStreamer) WriteFields(fields map[string]string) error {
+	var err error
+
+	for key, value := range fields {
+		err = m.bodyWriter.WriteField(key, value)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// WriteReader adds an io.Reader to get the content of a file.  The reader is
+// not accessed until the multipart.Reader is copied to some output writer.
+func (m *MultipartStreamer) WriteReader(key, filename string, size int64, reader io.Reader) (err error) {
+	m.reader = reader
+	m.contentLength = size
+
+	_, err = m.bodyWriter.CreateFormFile(key, filename)
+	return
+}
+
+// WriteFile is a shortcut for adding a local file as an io.Reader.
+func (m *MultipartStreamer) WriteFile(key, filename string) error {
+	fh, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+
+	stat, err := fh.Stat()
+	if err != nil {
+		return err
+	}
+
+	return m.WriteReader(key, filepath.Base(filename), stat.Size(), fh)
+}
+
+// SetupRequest sets up the http.Request body, and some crucial HTTP headers.
+func (m *MultipartStreamer) SetupRequest(req *http.Request) {
+	req.Body = m.GetReader()
+	req.Header.Add("Content-Type", m.ContentType)
+	req.ContentLength = m.Len()
+}
+
+func (m *MultipartStreamer) Boundary() string {
+	return m.bodyWriter.Boundary()
+}
+
+// Len calculates the byte size of the multipart content.
+func (m *MultipartStreamer) Len() int64 {
+	return m.contentLength + int64(m.bodyBuffer.Len()) + int64(m.closeBuffer.Len())
+}
+
+// GetReader gets an io.ReadCloser for passing to an http.Request.
+func (m *MultipartStreamer) GetReader() io.ReadCloser {
+	reader := io.MultiReader(m.bodyBuffer, m.reader, m.closeBuffer)
+	return ioutil.NopCloser(reader)
+}