package keepclient
import (
- //"net/http"
+ "crypto/md5"
+ "crypto/tls"
+ "encoding/json"
+ "errors"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "log"
+ "net/http"
"os"
+ "sort"
+ "strconv"
)
type KeepClient struct {
- apiServer string
- apiToken string
- apiInsecure bool
+ ApiServer string
+ ApiToken string
+ ApiInsecure bool
+ Service_roots []string
+ Want_replicas int
+ client *http.Client
}
-func InitKeepClient() *KeepClient {
- kc := KeepClient{os.Getenv("ARVADOS_API_HOST"),
- os.Getenv("ARVADOS_API_TOKEN"),
- os.Getenv("ARVADOS_API_HOST_INSECURE") != ""}
+type KeepDisk struct {
+ Hostname string `json:"service_host"`
+ Port int `json:"service_port"`
+ SSL bool `json:"service_ssl_flag"`
+}
+
+func MakeKeepClient() (kc *KeepClient, err error) {
+ kc = &KeepClient{
+ ApiServer: os.Getenv("ARVADOS_API_HOST"),
+ ApiToken: os.Getenv("ARVADOS_API_TOKEN"),
+ ApiInsecure: (os.Getenv("ARVADOS_API_HOST_INSECURE") != "")}
+
+ tr := &http.Transport{
+ TLSClientConfig: &tls.Config{InsecureSkipVerify: kc.ApiInsecure},
+ }
+
+ kc.client = &http.Client{Transport: tr}
+
+ err = kc.DiscoverKeepDisks()
+
+ return kc, err
+}
+
+func (this *KeepClient) DiscoverKeepDisks() error {
+ // Construct request of keep disk list
+ var req *http.Request
+ 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
+ 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 err
+ }
+
+ 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"
+ }
+
+ // 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)
+ }
+ }
+
+ // Must be sorted for ShuffledServiceRoots() to produce consistent
+ // results.
+ sort.Strings(this.Service_roots)
+
+ return nil
+}
+
+func (this KeepClient) ShuffledServiceRoots(hash string) (pseq []string) {
+ // Build an ordering with which to query the Keep servers based on the
+ // contents of the hash. "hash" is a hex-encoded number at least 8
+ // digits (32 bits) long
+
+ // seed used to calculate the next keep server from 'pool' to be added
+ // to 'pseq'
+ seed := hash
+
+ // Keep servers still to be added to the ordering
+ pool := make([]string, len(this.Service_roots))
+ copy(pool, this.Service_roots)
+
+ // output probe sequence
+ pseq = make([]string, 0, len(this.Service_roots))
+
+ // iterate while there are servers left to be assigned
+ for len(pool) > 0 {
+
+ if len(seed) < 8 {
+ // ran out of digits in the seed
+ if len(pseq) < (len(hash) / 4) {
+ // the number of servers added to the probe
+ // sequence is less than the number of 4-digit
+ // slices in 'hash' so refill the seed with the
+ // last 4 digits.
+ seed = hash[len(hash)-4:]
+ }
+ seed += hash
+ }
+
+ // Take the next 8 digits (32 bytes) and interpret as an integer,
+ // then modulus with the size of the remaining pool to get the next
+ // selected server.
+ probe, _ := strconv.ParseUint(seed[0:8], 16, 32)
+ probe %= uint64(len(pool))
+
+ // Append the selected server to the probe sequence and remove it
+ // from the pool.
+ pseq = append(pseq, pool[probe])
+ pool = append(pool[:probe], pool[probe+1:]...)
+
+ // Remove the digits just used from the seed
+ seed = seed[8:]
+ }
+ return pseq
+}
+
+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 {
+ log.Printf("ReadIntoBuffer doing read")
+ 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 {
+ log.Printf("ReadIntoBuffer sending error %d %s", n, err.Error())
+ slices <- ReaderSlice{nil, err}
+ return
+ }
+
+ log.Printf("ReadIntoBuffer got %d", n)
+
+ if n > 0 {
+ log.Printf("ReadIntoBuffer sending readerslice")
+ // Make a slice with the contents of the read
+ slices <- ReaderSlice{ptr[:n], nil}
+ log.Printf("ReadIntoBuffer sent readerslice")
+
+ // Adjust the scratch space slice
+ ptr = ptr[n:]
+ }
+ }
+}
+
+// A read request to the Transfer() function
+type ReadRequest struct {
+ offset int
+ p []byte
+ result chan<- ReadResult
+}
+
+// A read result from the Transfer() function
+type ReadResult struct {
+ n int
+ 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, p, this.responses}
+ rr, valid := <-this.responses
+ if valid {
+ *this.offset += rr.n
+ return rr.n, rr.err
+ } else {
+ return 0, 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 %t", req.offset, len(body), complete)
+ if req.offset < len(body) {
+ req.result <- ReadResult{copy(req.p, body[req.offset:]), nil}
+ return true
+ } else if complete && req.offset >= len(body) {
+ req.result <- ReadResult{0, 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
+ 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 {
+ log.Printf("Doing select")
+ select {
+ case req, valid := <-requests:
+ log.Printf("Got read request")
+ // Handle a buffer read request
+ if valid {
+ if !HandleReadRequest(req, body, complete) {
+ log.Printf("Queued")
+ 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 {
+ log.Printf("Got readerslice %d", len(bk.slice))
+
+ 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) {
+ log.Printf("ReadRequest handled")
+
+ // 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 {
+ log.Printf("ReadRequest re-queued")
+
+ // 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 UploadError struct {
+ err error
+ url string
+}
+
+func (this KeepClient) uploadToKeepServer(host string, hash string, body io.ReadCloser, upload_status chan<- UploadError) {
+ 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 <- UploadError{err, url}
+ return
+ }
+
+ req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", this.ApiToken))
+ req.Body = body
+
+ var resp *http.Response
+ if resp, err = this.client.Do(req); err != nil {
+ upload_status <- UploadError{err, url}
+ }
+
+ if resp.StatusCode == http.StatusOK {
+ upload_status <- UploadError{io.EOF, url}
+ }
+}
+
+var KeepWriteError = errors.New("Could not write sufficient replicas")
+
+func (this KeepClient) putReplicas(
+ hash string,
+ requests chan ReadRequest,
+ reader_status chan error) 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 UploadError)
+ defer close(upload_status)
+
+ // Desired number of replicas
+ want_replicas := this.Want_replicas
+
+ for want_replicas > 0 {
+ for active < want_replicas {
+ // Start some upload requests
+ if next_server < len(sv) {
+ go this.uploadToKeepServer(sv[next_server], hash, MakeBufferReader(requests), upload_status)
+ next_server += 1
+ active += 1
+ } else {
+ return KeepWriteError
+ }
+ }
+
+ // Now wait for something to happen.
+ select {
+ case status := <-reader_status:
+ if status == io.EOF {
+ // good news!
+ } else {
+ // bad news
+ return status
+ }
+ case status := <-upload_status:
+ if status.err == io.EOF {
+ // good news!
+ want_replicas -= 1
+ } else {
+ // writing to keep server failed for some reason
+ log.Printf("Got error %s uploading to %s", status.err, status.url)
+ }
+ active -= 1
+ }
+ }
+
+ return nil
+}
+
+func (this KeepClient) PutHR(hash string, r io.Reader) error {
+
+ // Buffer for reads from 'r'
+ buffer := make([]byte, 64*1024*1024)
+
+ // Read requests on Transfer() buffer
+ requests := make(chan ReadRequest)
+ defer close(requests)
+
+ // Reporting reader error states
+ reader_status := make(chan error)
+
+ // Start the transfer goroutine
+ go Transfer(buffer, r, requests, reader_status)
+
+ return this.putReplicas(hash, requests, reader_status)
+}
+
+func (this KeepClient) PutHB(hash string, buffer []byte) 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)
+}
+
+func (this KeepClient) PutB(buffer []byte) error {
+ return this.PutHB(fmt.Sprintf("%x", md5.Sum(buffer)), buffer)
+}
- return &kc
+func (this KeepClient) PutR(r io.Reader) error {
+ if buffer, err := ioutil.ReadAll(r); err != nil {
+ return err
+ } else {
+ return this.PutB(buffer)
+ }
}
projects / arvados.git / blobdiff