2798: Added AuthorizedGet(), Ask() and AuthorizedAsk(). Added BLOCKSIZE
[arvados.git] / sdk / go / src / arvados.org / keepclient / keepclient.go
index 9c1210dfd8882774175602396e47cf4e411106f2..2738cefa7c3144ec613aa8b6f8d6922e33debc44 100644 (file)
@@ -1,17 +1,33 @@
 package keepclient
 
 import (
+       "crypto/md5"
        "crypto/tls"
        "encoding/json"
+       "errors"
        "fmt"
        "io"
+       "io/ioutil"
+       "log"
        "net/http"
+       "os"
        "sort"
        "strconv"
 )
 
+// A Keep "block" is 64MB.
+const BLOCKSIZE = 64 * 1024 * 1024
+
+var BlockNotFound = errors.New("Block not found")
+var InsufficientReplicasError = errors.New("Could not write sufficient replicas")
+
 type KeepClient struct {
+       ApiServer     string
+       ApiToken      string
+       ApiInsecure   bool
        Service_roots []string
+       Want_replicas int
+       Client        *http.Client
 }
 
 type KeepDisk struct {
@@ -20,51 +36,75 @@ type KeepDisk struct {
        SSL      bool   `json:"service_ssl_flag"`
 }
 
-func KeepDisks() (service_roots []string, err error) {
+func MakeKeepClient() (kc KeepClient, err error) {
        tr := &http.Transport{
-               TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+               TLSClientConfig: &tls.Config{InsecureSkipVerify: kc.ApiInsecure},
        }
-       client := &http.Client{Transport: tr}
 
+       kc = KeepClient{
+               ApiServer:     os.Getenv("ARVADOS_API_HOST"),
+               ApiToken:      os.Getenv("ARVADOS_API_TOKEN"),
+               ApiInsecure:   (os.Getenv("ARVADOS_API_HOST_INSECURE") != ""),
+               Want_replicas: 2,
+               Client:        &http.Client{Transport: tr}}
+
+       err = (&kc).DiscoverKeepServers()
+
+       return kc, err
+}
+
+func (this *KeepClient) DiscoverKeepServers() error {
+       // Construct request of keep disk list
        var req *http.Request
-       if req, err = http.NewRequest("GET", "https://localhost:3001/arvados/v1/keep_disks", nil); err != nil {
-               return nil, err
+       var err error
+       if req, err = http.NewRequest("GET", fmt.Sprintf("https://%s/arvados/v1/keep_disks", this.ApiServer), nil); err != nil {
+               return err
        }
 
+       // Add api token header
+       req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", this.ApiToken))
+
+       // Make the request
        var resp *http.Response
-       req.Header.Add("Authorization", "OAuth2 4axaw8zxe0qm22wa6urpp5nskcne8z88cvbupv653y1njyi05h")
-       if resp, err = client.Do(req); err != nil {
-               return nil, err
+       if resp, err = this.Client.Do(req); err != nil {
+               return err
        }
 
        type SvcList struct {
                Items []KeepDisk `json:"items"`
        }
+
+       // Decode json reply
        dec := json.NewDecoder(resp.Body)
        var m SvcList
        if err := dec.Decode(&m); err != nil {
-               return nil, err
+               return err
        }
 
-       service_roots = make([]string, len(m.Items))
-       for index, element := range m.Items {
+       listed := make(map[string]bool)
+       this.Service_roots = make([]string, 0, len(m.Items))
+
+       for _, element := range m.Items {
                n := ""
                if element.SSL {
                        n = "s"
                }
-               service_roots[index] = fmt.Sprintf("http%s://%s:%d",
-                       n, element.Hostname, element.Port)
-       }
-       sort.Strings(service_roots)
-       return service_roots, nil
-}
 
-func MakeKeepClient() (kc *KeepClient, err error) {
-       sv, err := KeepDisks()
-       if err != nil {
-               return nil, err
+               // Construct server URL
+               url := fmt.Sprintf("http%s://%s:%d", n, element.Hostname, element.Port)
+
+               // Skip duplicates
+               if !listed[url] {
+                       listed[url] = true
+                       this.Service_roots = append(this.Service_roots, url)
+               }
        }
-       return &KeepClient{sv}, nil
+
+       // Must be sorted for ShuffledServiceRoots() to produce consistent
+       // results.
+       sort.Strings(this.Service_roots)
+
+       return nil
 }
 
 func (this KeepClient) ShuffledServiceRoots(hash string) (pseq []string) {
@@ -115,27 +155,474 @@ func (this KeepClient) ShuffledServiceRoots(hash string) (pseq []string) {
        return pseq
 }
 
-func Fill(buffer []byte, r io.Reader, c chan []byte, errorchan chan error) {
-       ptr := buffer[:]
+type ReaderSlice struct {
+       slice        []byte
+       reader_error error
+}
 
+// Read repeatedly from the reader into the specified buffer, and report each
+// read to channel 'c'.  Completes when Reader 'r' reports on the error channel
+// and closes channel 'c'.
+func ReadIntoBuffer(buffer []byte, r io.Reader, slices chan<- ReaderSlice) {
+       defer close(slices)
+
+       // Initially use entire buffer as scratch space
+       ptr := buffer[:]
        for {
-               n, err := r.Read(ptr)
+               var n int
+               var err error
+               if len(ptr) > 0 {
+                       // Read into the scratch space
+                       n, err = r.Read(ptr)
+               } else {
+                       // Ran out of scratch space, try reading one more byte
+                       var b [1]byte
+                       n, err = r.Read(b[:])
+
+                       if n > 0 {
+                               // Reader has more data but we have nowhere to
+                               // put it, so we're stuffed
+                               slices <- ReaderSlice{nil, io.ErrShortBuffer}
+                       } else {
+                               // Return some other error (hopefully EOF)
+                               slices <- ReaderSlice{nil, err}
+                       }
+                       return
+               }
+
+               // End on error (includes EOF)
                if err != nil {
-                       errorchan <- err
+                       slices <- ReaderSlice{nil, err}
                        return
                }
-               c <- ptr[:n]
-               ptr = ptr[n:]
+
+               if n > 0 {
+                       // Make a slice with the contents of the read
+                       slices <- ReaderSlice{ptr[:n], nil}
+
+                       // Adjust the scratch space slice
+                       ptr = ptr[n:]
+               }
+       }
+}
+
+// A read request to the Transfer() function
+type ReadRequest struct {
+       offset  int
+       maxsize int
+       result  chan<- ReadResult
+}
+
+// A read result from the Transfer() function
+type ReadResult struct {
+       slice []byte
+       err   error
+}
+
+// Reads from the buffer managed by the Transfer()
+type BufferReader struct {
+       offset    *int
+       requests  chan<- ReadRequest
+       responses chan ReadResult
+}
+
+func MakeBufferReader(requests chan<- ReadRequest) BufferReader {
+       return BufferReader{new(int), requests, make(chan ReadResult)}
+}
+
+// Reads from the buffer managed by the Transfer()
+func (this BufferReader) Read(p []byte) (n int, err error) {
+       this.requests <- ReadRequest{*this.offset, len(p), this.responses}
+       rr, valid := <-this.responses
+       if valid {
+               *this.offset += len(rr.slice)
+               return copy(p, rr.slice), rr.err
+       } else {
+               return 0, io.ErrUnexpectedEOF
+       }
+}
+
+func (this BufferReader) WriteTo(dest io.Writer) (written int64, err error) {
+       // Record starting offset in order to correctly report the number of bytes sent
+       starting_offset := *this.offset
+       for {
+               this.requests <- ReadRequest{*this.offset, 32 * 1024, this.responses}
+               rr, valid := <-this.responses
+               if valid {
+                       log.Printf("WriteTo slice %v %d %v", *this.offset, len(rr.slice), rr.err)
+                       *this.offset += len(rr.slice)
+                       if rr.err != nil {
+                               if rr.err == io.EOF {
+                                       // EOF is not an error.
+                                       return int64(*this.offset - starting_offset), nil
+                               } else {
+                                       return int64(*this.offset - starting_offset), rr.err
+                               }
+                       } else {
+                               dest.Write(rr.slice)
+                       }
+               } else {
+                       return int64(*this.offset), io.ErrUnexpectedEOF
+               }
+       }
+}
+
+// Close the responses channel
+func (this BufferReader) Close() error {
+       close(this.responses)
+       return nil
+}
+
+// Handle a read request.  Returns true if a response was sent, and false if
+// the request should be queued.
+func HandleReadRequest(req ReadRequest, body []byte, complete bool) bool {
+       log.Printf("HandleReadRequest %d %d %d", req.offset, req.maxsize, len(body))
+       if req.offset < len(body) {
+               var end int
+               if req.offset+req.maxsize < len(body) {
+                       end = req.offset + req.maxsize
+               } else {
+                       end = len(body)
+               }
+               req.result <- ReadResult{body[req.offset:end], nil}
+               return true
+       } else if complete && req.offset >= len(body) {
+               req.result <- ReadResult{nil, io.EOF}
+               return true
+       } else {
+               return false
+       }
+}
+
+// If 'source_reader' is not nil, reads data from 'source_reader' and stores it
+// in the provided buffer.  Otherwise, use the contents of 'buffer' as is.
+// Accepts read requests on the buffer on the 'requests' channel.  Completes
+// when 'requests' channel is closed.
+func Transfer(source_buffer []byte, source_reader io.Reader, requests <-chan ReadRequest, reader_error chan error) {
+       // currently buffered data
+       var body []byte
+
+       // for receiving slices from ReadIntoBuffer
+       var slices chan ReaderSlice = nil
+
+       // indicates whether the buffered data is complete
+       var complete bool = false
+
+       if source_reader != nil {
+               // 'body' is the buffer slice representing the body content read so far
+               body = source_buffer[:0]
+
+               // used to communicate slices of the buffer as they are
+               // ReadIntoBuffer will close 'slices' when it is done with it
+               slices = make(chan ReaderSlice)
+
+               // Spin it off
+               go ReadIntoBuffer(source_buffer, source_reader, slices)
+       } else {
+               // use the whole buffer
+               body = source_buffer[:]
+
+               // buffer is complete
+               complete = true
+       }
+
+       pending_requests := make([]ReadRequest, 0)
+
+       for {
+               select {
+               case req, valid := <-requests:
+                       // Handle a buffer read request
+                       if valid {
+                               if !HandleReadRequest(req, body, complete) {
+                                       pending_requests = append(pending_requests, req)
+                               }
+                       } else {
+                               // closed 'requests' channel indicates we're done
+                               return
+                       }
+
+               case bk, valid := <-slices:
+                       // Got a new slice from the reader
+                       if valid {
+                               if bk.reader_error != nil {
+                                       reader_error <- bk.reader_error
+                                       if bk.reader_error == io.EOF {
+                                               // EOF indicates the reader is done
+                                               // sending, so our buffer is complete.
+                                               complete = true
+                                       } else {
+                                               // some other reader error
+                                               return
+                                       }
+                               }
+
+                               if bk.slice != nil {
+                                       // adjust body bounds now that another slice has been read
+                                       body = source_buffer[0 : len(body)+len(bk.slice)]
+                               }
+
+                               // handle pending reads
+                               n := 0
+                               for n < len(pending_requests) {
+                                       if HandleReadRequest(pending_requests[n], body, complete) {
+
+                                               // move the element from the
+                                               // back of the slice to
+                                               // position 'n', then shorten
+                                               // the slice by one element
+                                               pending_requests[n] = pending_requests[len(pending_requests)-1]
+                                               pending_requests = pending_requests[0 : len(pending_requests)-1]
+                                       } else {
+
+                                               // Request wasn't handled, so keep it in the request slice
+                                               n += 1
+                                       }
+                               }
+                       } else {
+                               if complete {
+                                       // no more reads
+                                       slices = nil
+                               } else {
+                                       // reader channel closed without signaling EOF
+                                       reader_error <- io.ErrUnexpectedEOF
+                                       return
+                               }
+                       }
+               }
+       }
+}
+
+type UploadStatus struct {
+       Err        error
+       Url        string
+       StatusCode int
+}
+
+func (this KeepClient) uploadToKeepServer(host string, hash string, body io.ReadCloser,
+       upload_status chan<- UploadStatus, expectedLength int64) {
+
+       log.Printf("Uploading to %s", host)
+
+       var req *http.Request
+       var err error
+       var url = fmt.Sprintf("%s/%s", host, hash)
+       if req, err = http.NewRequest("PUT", url, nil); err != nil {
+               upload_status <- UploadStatus{err, url, 0}
+               return
+       }
+
+       if expectedLength > 0 {
+               req.ContentLength = expectedLength
+       }
+
+       req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", this.ApiToken))
+       req.Header.Add("Content-Type", "application/octet-stream")
+       req.Body = body
+
+       var resp *http.Response
+       if resp, err = this.Client.Do(req); err != nil {
+               upload_status <- UploadStatus{err, url, 0}
+               return
+       }
+
+       if resp.StatusCode == http.StatusOK {
+               upload_status <- UploadStatus{nil, url, resp.StatusCode}
+       } else {
+               upload_status <- UploadStatus{errors.New(resp.Status), url, resp.StatusCode}
+       }
+}
+
+func (this KeepClient) putReplicas(
+       hash string,
+       requests chan ReadRequest,
+       reader_status chan error,
+       expectedLength int64) (replicas int, err error) {
+
+       // Calculate the ordering for uploading to servers
+       sv := this.ShuffledServiceRoots(hash)
+
+       // The next server to try contacting
+       next_server := 0
+
+       // The number of active writers
+       active := 0
+
+       // Used to communicate status from the upload goroutines
+       upload_status := make(chan UploadStatus)
+       defer close(upload_status)
+
+       // Desired number of replicas
+       remaining_replicas := this.Want_replicas
+
+       for remaining_replicas > 0 {
+               for active < remaining_replicas {
+                       // Start some upload requests
+                       if next_server < len(sv) {
+                               go this.uploadToKeepServer(sv[next_server], hash, MakeBufferReader(requests), upload_status, expectedLength)
+                               next_server += 1
+                               active += 1
+                       } else {
+                               return (this.Want_replicas - remaining_replicas), InsufficientReplicasError
+                       }
+               }
+
+               // Now wait for something to happen.
+               select {
+               case status := <-reader_status:
+                       if status == io.EOF {
+                               // good news!
+                       } else {
+                               // bad news
+                               return (this.Want_replicas - remaining_replicas), status
+                       }
+               case status := <-upload_status:
+                       if status.StatusCode == 200 {
+                               // good news!
+                               remaining_replicas -= 1
+                       } else {
+                               // writing to keep server failed for some reason
+                               log.Printf("Keep server put to %v failed with '%v'",
+                                       status.Url, status.Err)
+                       }
+                       active -= 1
+                       log.Printf("Upload status %v %v %v", status.StatusCode, remaining_replicas, active)
+               }
        }
+
+       return (this.Want_replicas - remaining_replicas), nil
+}
+
+var OversizeBlockError = errors.New("Block too big")
+
+func (this KeepClient) PutHR(hash string, r io.Reader, expectedLength int64) (replicas int, err error) {
+
+       // Buffer for reads from 'r'
+       var buffer []byte
+       if expectedLength > 0 {
+               if expectedLength > BLOCKSIZE {
+                       return 0, OversizeBlockError
+               }
+               buffer = make([]byte, expectedLength)
+       } else {
+               buffer = make([]byte, BLOCKSIZE)
+       }
+
+       // Read requests on Transfer() buffer
+       requests := make(chan ReadRequest)
+       defer close(requests)
+
+       // Reporting reader error states
+       reader_status := make(chan error)
+       defer close(reader_status)
+
+       // Start the transfer goroutine
+       go Transfer(buffer, r, requests, reader_status)
+
+       return this.putReplicas(hash, requests, reader_status, expectedLength)
 }
 
-func (this KeepClient) KeepPut(hash string, r io.Reader) {
-       //sv := this.ShuffledServiceRoots(hash)
-       //n := 0
-       buffer := make([]byte, 0, 1024*1024*64)
-       //success := make(chan int)
-       reads := make(chan []byte)
-       errorchan := make(chan error)
+func (this KeepClient) PutHB(hash string, buffer []byte) (replicas int, err error) {
+       // Read requests on Transfer() buffer
+       requests := make(chan ReadRequest)
+       defer close(requests)
+
+       // Start the transfer goroutine
+       go Transfer(buffer, nil, requests, nil)
+
+       return this.putReplicas(hash, requests, nil, int64(len(buffer)))
+}
+
+func (this KeepClient) PutB(buffer []byte) (hash string, replicas int, err error) {
+       hash = fmt.Sprintf("%x", md5.Sum(buffer))
+       replicas, err = this.PutHB(hash, buffer)
+       return hash, replicas, err
+}
+
+func (this KeepClient) PutR(r io.Reader) (hash string, replicas int, err error) {
+       if buffer, err := ioutil.ReadAll(r); err != nil {
+               return "", 0, err
+       } else {
+               return this.PutB(buffer)
+       }
+}
+
+func (this KeepClient) Get(hash string) (reader io.ReadCloser,
+       contentLength int64, url string, err error) {
+       return this.AuthorizedGet(hash, "", "")
+}
+
+func (this KeepClient) AuthorizedGet(hash string,
+       signature string,
+       timestamp string) (reader io.ReadCloser,
+       contentLength int64, url string, err error) {
+
+       // Calculate the ordering for asking servers
+       sv := this.ShuffledServiceRoots(hash)
+
+       for _, host := range sv {
+               var req *http.Request
+               var err error
+               var url string
+               if signature != "" {
+                       url = fmt.Sprintf("%s/%s+A%s@%s", host, hash,
+                               signature, timestamp)
+               } else {
+                       url = fmt.Sprintf("%s/%s", host, hash)
+               }
+               if req, err = http.NewRequest("GET", url, nil); err != nil {
+                       continue
+               }
+
+               req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", this.ApiToken))
+
+               var resp *http.Response
+               if resp, err = this.Client.Do(req); err != nil {
+                       continue
+               }
+
+               if resp.StatusCode == http.StatusOK {
+                       return resp.Body, resp.ContentLength, url, nil
+               }
+       }
+
+       return nil, 0, "", BlockNotFound
+}
+
+func (this KeepClient) Ask(hash string) (contentLength int64, url string, err error) {
+       return this.AuthorizedAsk(hash, "", "")
+}
+
+func (this KeepClient) AuthorizedAsk(hash string, signature string,
+       timestamp string) (contentLength int64, url string, err error) {
+       // Calculate the ordering for asking servers
+       sv := this.ShuffledServiceRoots(hash)
+
+       for _, host := range sv {
+               var req *http.Request
+               var err error
+               if signature != "" {
+                       url = fmt.Sprintf("%s/%s+A%s@%s", host, hash,
+                               signature, timestamp)
+               } else {
+                       url = fmt.Sprintf("%s/%s", host, hash)
+               }
+
+               if req, err = http.NewRequest("HEAD", url, nil); err != nil {
+                       continue
+               }
+
+               req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", this.ApiToken))
+
+               var resp *http.Response
+               if resp, err = this.Client.Do(req); err != nil {
+                       continue
+               }
+
+               if resp.StatusCode == http.StatusOK {
+                       return resp.ContentLength, url, nil
+               }
+       }
+
+       return 0, "", BlockNotFound
 
-       go Fill(buffer, r, reads, errorchan)
 }