plugeth/vendor/github.com/Azure/azure-storage-go/file.go

413 lines
12 KiB
Go
Raw Normal View History

package storage
import (
"errors"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"strconv"
)
const fourMB = uint64(4194304)
const oneTB = uint64(1099511627776)
// File represents a file on a share.
type File struct {
fsc *FileServiceClient
Metadata map[string]string
Name string `xml:"Name"`
parent *Directory
Properties FileProperties `xml:"Properties"`
share *Share
FileCopyProperties FileCopyState
}
// FileProperties contains various properties of a file.
type FileProperties struct {
CacheControl string `header:"x-ms-cache-control"`
Disposition string `header:"x-ms-content-disposition"`
Encoding string `header:"x-ms-content-encoding"`
Etag string
Language string `header:"x-ms-content-language"`
LastModified string
Length uint64 `xml:"Content-Length"`
MD5 string `header:"x-ms-content-md5"`
Type string `header:"x-ms-content-type"`
}
// FileCopyState contains various properties of a file copy operation.
type FileCopyState struct {
CompletionTime string
ID string `header:"x-ms-copy-id"`
Progress string
Source string
Status string `header:"x-ms-copy-status"`
StatusDesc string
}
// FileStream contains file data returned from a call to GetFile.
type FileStream struct {
Body io.ReadCloser
ContentMD5 string
}
// FileRequestOptions will be passed to misc file operations.
// Currently just Timeout (in seconds) but will expand.
type FileRequestOptions struct {
Timeout uint // timeout duration in seconds.
}
// getParameters, construct parameters for FileRequestOptions.
// currently only timeout, but expecting to grow as functionality fills out.
func (p FileRequestOptions) getParameters() url.Values {
out := url.Values{}
if p.Timeout != 0 {
out.Set("timeout", fmt.Sprintf("%v", p.Timeout))
}
return out
}
// FileRanges contains a list of file range information for a file.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn166984.aspx
type FileRanges struct {
ContentLength uint64
LastModified string
ETag string
FileRanges []FileRange `xml:"Range"`
}
// FileRange contains range information for a file.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn166984.aspx
type FileRange struct {
Start uint64 `xml:"Start"`
End uint64 `xml:"End"`
}
func (fr FileRange) String() string {
return fmt.Sprintf("bytes=%d-%d", fr.Start, fr.End)
}
// builds the complete file path for this file object
func (f *File) buildPath() string {
return f.parent.buildPath() + "/" + f.Name
}
// ClearRange releases the specified range of space in a file.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn194276.aspx
func (f *File) ClearRange(fileRange FileRange) error {
headers, err := f.modifyRange(nil, fileRange, nil)
if err != nil {
return err
}
f.updateEtagAndLastModified(headers)
return nil
}
// Create creates a new file or replaces an existing one.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn194271.aspx
func (f *File) Create(maxSize uint64) error {
if maxSize > oneTB {
return fmt.Errorf("max file size is 1TB")
}
extraHeaders := map[string]string{
"x-ms-content-length": strconv.FormatUint(maxSize, 10),
"x-ms-type": "file",
}
headers, err := f.fsc.createResource(f.buildPath(), resourceFile, nil, mergeMDIntoExtraHeaders(f.Metadata, extraHeaders), []int{http.StatusCreated})
if err != nil {
return err
}
f.Properties.Length = maxSize
f.updateEtagAndLastModified(headers)
return nil
}
// CopyFile operation copied a file/blob from the sourceURL to the path provided.
//
// See https://docs.microsoft.com/en-us/rest/api/storageservices/fileservices/copy-file
func (f *File) CopyFile(sourceURL string, options *FileRequestOptions) error {
extraHeaders := map[string]string{
"x-ms-type": "file",
"x-ms-copy-source": sourceURL,
}
var parameters url.Values
if options != nil {
parameters = options.getParameters()
}
headers, err := f.fsc.createResource(f.buildPath(), resourceFile, parameters, mergeMDIntoExtraHeaders(f.Metadata, extraHeaders), []int{http.StatusAccepted})
if err != nil {
return err
}
f.updateEtagLastModifiedAndCopyHeaders(headers)
return nil
}
// Delete immediately removes this file from the storage account.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn689085.aspx
func (f *File) Delete() error {
return f.fsc.deleteResource(f.buildPath(), resourceFile)
}
// DeleteIfExists removes this file if it exists.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn689085.aspx
func (f *File) DeleteIfExists() (bool, error) {
resp, err := f.fsc.deleteResourceNoClose(f.buildPath(), resourceFile)
if resp != nil {
defer readAndCloseBody(resp.body)
if resp.statusCode == http.StatusAccepted || resp.statusCode == http.StatusNotFound {
return resp.statusCode == http.StatusAccepted, nil
}
}
return false, err
}
// DownloadRangeToStream operation downloads the specified range of this file with optional MD5 hash.
//
// See https://docs.microsoft.com/en-us/rest/api/storageservices/fileservices/get-file
func (f *File) DownloadRangeToStream(fileRange FileRange, getContentMD5 bool) (fs FileStream, err error) {
if getContentMD5 && isRangeTooBig(fileRange) {
return fs, fmt.Errorf("must specify a range less than or equal to 4MB when getContentMD5 is true")
}
extraHeaders := map[string]string{
"Range": fileRange.String(),
}
if getContentMD5 == true {
extraHeaders["x-ms-range-get-content-md5"] = "true"
}
resp, err := f.fsc.getResourceNoClose(f.buildPath(), compNone, resourceFile, http.MethodGet, extraHeaders)
if err != nil {
return fs, err
}
if err = checkRespCode(resp.statusCode, []int{http.StatusOK, http.StatusPartialContent}); err != nil {
resp.body.Close()
return fs, err
}
fs.Body = resp.body
if getContentMD5 {
fs.ContentMD5 = resp.headers.Get("Content-MD5")
}
return fs, nil
}
// Exists returns true if this file exists.
func (f *File) Exists() (bool, error) {
exists, headers, err := f.fsc.resourceExists(f.buildPath(), resourceFile)
if exists {
f.updateEtagAndLastModified(headers)
f.updateProperties(headers)
}
return exists, err
}
// FetchAttributes updates metadata and properties for this file.
func (f *File) FetchAttributes() error {
headers, err := f.fsc.getResourceHeaders(f.buildPath(), compNone, resourceFile, http.MethodHead)
if err != nil {
return err
}
f.updateEtagAndLastModified(headers)
f.updateProperties(headers)
f.Metadata = getMetadataFromHeaders(headers)
return nil
}
// returns true if the range is larger than 4MB
func isRangeTooBig(fileRange FileRange) bool {
if fileRange.End-fileRange.Start > fourMB {
return true
}
return false
}
// ListRanges returns the list of valid ranges for this file.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn166984.aspx
func (f *File) ListRanges(listRange *FileRange) (*FileRanges, error) {
params := url.Values{"comp": {"rangelist"}}
// add optional range to list
var headers map[string]string
if listRange != nil {
headers = make(map[string]string)
headers["Range"] = listRange.String()
}
resp, err := f.fsc.listContent(f.buildPath(), params, headers)
if err != nil {
return nil, err
}
defer resp.body.Close()
var cl uint64
cl, err = strconv.ParseUint(resp.headers.Get("x-ms-content-length"), 10, 64)
if err != nil {
ioutil.ReadAll(resp.body)
return nil, err
}
var out FileRanges
out.ContentLength = cl
out.ETag = resp.headers.Get("ETag")
out.LastModified = resp.headers.Get("Last-Modified")
err = xmlUnmarshal(resp.body, &out)
return &out, err
}
// modifies a range of bytes in this file
func (f *File) modifyRange(bytes io.Reader, fileRange FileRange, contentMD5 *string) (http.Header, error) {
if err := f.fsc.checkForStorageEmulator(); err != nil {
return nil, err
}
if fileRange.End < fileRange.Start {
return nil, errors.New("the value for rangeEnd must be greater than or equal to rangeStart")
}
if bytes != nil && isRangeTooBig(fileRange) {
return nil, errors.New("range cannot exceed 4MB in size")
}
uri := f.fsc.client.getEndpoint(fileServiceName, f.buildPath(), url.Values{"comp": {"range"}})
// default to clear
write := "clear"
cl := uint64(0)
// if bytes is not nil then this is an update operation
if bytes != nil {
write = "update"
cl = (fileRange.End - fileRange.Start) + 1
}
extraHeaders := map[string]string{
"Content-Length": strconv.FormatUint(cl, 10),
"Range": fileRange.String(),
"x-ms-write": write,
}
if contentMD5 != nil {
extraHeaders["Content-MD5"] = *contentMD5
}
headers := mergeHeaders(f.fsc.client.getStandardHeaders(), extraHeaders)
resp, err := f.fsc.client.exec(http.MethodPut, uri, headers, bytes, f.fsc.auth)
if err != nil {
return nil, err
}
defer readAndCloseBody(resp.body)
return resp.headers, checkRespCode(resp.statusCode, []int{http.StatusCreated})
}
// SetMetadata replaces the metadata for this file.
//
// Some keys may be converted to Camel-Case before sending. All keys
// are returned in lower case by GetFileMetadata. HTTP header names
// are case-insensitive so case munging should not matter to other
// applications either.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn689097.aspx
func (f *File) SetMetadata() error {
headers, err := f.fsc.setResourceHeaders(f.buildPath(), compMetadata, resourceFile, mergeMDIntoExtraHeaders(f.Metadata, nil))
if err != nil {
return err
}
f.updateEtagAndLastModified(headers)
return nil
}
// SetProperties sets system properties on this file.
//
// Some keys may be converted to Camel-Case before sending. All keys
// are returned in lower case by SetFileProperties. HTTP header names
// are case-insensitive so case munging should not matter to other
// applications either.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn166975.aspx
func (f *File) SetProperties() error {
headers, err := f.fsc.setResourceHeaders(f.buildPath(), compProperties, resourceFile, headersFromStruct(f.Properties))
if err != nil {
return err
}
f.updateEtagAndLastModified(headers)
return nil
}
// updates Etag and last modified date
func (f *File) updateEtagAndLastModified(headers http.Header) {
f.Properties.Etag = headers.Get("Etag")
f.Properties.LastModified = headers.Get("Last-Modified")
}
// updates Etag, last modified date and x-ms-copy-id
func (f *File) updateEtagLastModifiedAndCopyHeaders(headers http.Header) {
f.Properties.Etag = headers.Get("Etag")
f.Properties.LastModified = headers.Get("Last-Modified")
f.FileCopyProperties.ID = headers.Get("X-Ms-Copy-Id")
f.FileCopyProperties.Status = headers.Get("X-Ms-Copy-Status")
}
// updates file properties from the specified HTTP header
func (f *File) updateProperties(header http.Header) {
size, err := strconv.ParseUint(header.Get("Content-Length"), 10, 64)
if err == nil {
f.Properties.Length = size
}
f.updateEtagAndLastModified(header)
f.Properties.CacheControl = header.Get("Cache-Control")
f.Properties.Disposition = header.Get("Content-Disposition")
f.Properties.Encoding = header.Get("Content-Encoding")
f.Properties.Language = header.Get("Content-Language")
f.Properties.MD5 = header.Get("Content-MD5")
f.Properties.Type = header.Get("Content-Type")
}
// URL gets the canonical URL to this file.
// This method does not create a publicly accessible URL if the file
// is private and this method does not check if the file exists.
func (f *File) URL() string {
return f.fsc.client.getEndpoint(fileServiceName, f.buildPath(), url.Values{})
}
// WriteRange writes a range of bytes to this file with an optional MD5 hash of the content.
// Note that the length of bytes must match (rangeEnd - rangeStart) + 1 with a maximum size of 4MB.
//
// See https://msdn.microsoft.com/en-us/library/azure/dn194276.aspx
func (f *File) WriteRange(bytes io.Reader, fileRange FileRange, contentMD5 *string) error {
if bytes == nil {
return errors.New("bytes cannot be nil")
}
headers, err := f.modifyRange(bytes, fileRange, contentMD5)
if err != nil {
return err
}
f.updateEtagAndLastModified(headers)
return nil
}