+++ /dev/null
-/* Provides low-level Get/Put primitives for accessing Arvados Keep blocks. */
-package keepclient
-
-import (
- "arvados.org/sdk"
- "arvados.org/streamer"
- "crypto/md5"
- "errors"
- "fmt"
- "io"
- "io/ioutil"
- "log"
- "net/http"
- "regexp"
- "sort"
- "strings"
- "sync"
- "sync/atomic"
- "unsafe"
-)
-
-// 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")
-var OversizeBlockError = errors.New("Block too big")
-var MissingArvadosApiHost = errors.New("Missing required environment variable ARVADOS_API_HOST")
-var MissingArvadosApiToken = errors.New("Missing required environment variable ARVADOS_API_TOKEN")
-
-const X_Keep_Desired_Replicas = "X-Keep-Desired-Replicas"
-const X_Keep_Replicas_Stored = "X-Keep-Replicas-Stored"
-
-// Information about Arvados and Keep servers.
-type KeepClient struct {
- Arvados *sdk.ArvadosClient
- Want_replicas int
- Using_proxy bool
- service_roots *[]string
- lock sync.Mutex
- Client *http.Client
-}
-
-// Create a new KeepClient. This will contact the API server to discover Keep
-// servers.
-func MakeKeepClient(arv *sdk.ArvadosClient) (kc KeepClient, err error) {
- kc = KeepClient{
- Arvados: arv,
- Want_replicas: 2,
- Using_proxy: false,
- Client: &http.Client{Transport: &http.Transport{}}}
-
- err = (&kc).DiscoverKeepServers()
-
- return kc, err
-}
-
-// Put a block given the block hash, a reader with the block data, and the
-// expected length of that data. The desired number of replicas is given in
-// KeepClient.Want_replicas. Returns the number of replicas that were written
-// and if there was an error. Note this will return InsufficientReplias
-// whenever 0 <= replicas < this.Wants_replicas.
-func (this KeepClient) PutHR(hash string, r io.Reader, expectedLength int64) (locator string, replicas int, err error) {
-
- // Buffer for reads from 'r'
- var bufsize int
- if expectedLength > 0 {
- if expectedLength > BLOCKSIZE {
- return "", 0, OversizeBlockError
- }
- bufsize = int(expectedLength)
- } else {
- bufsize = BLOCKSIZE
- }
-
- t := streamer.AsyncStreamFromReader(bufsize, HashCheckingReader{r, md5.New(), hash})
- defer t.Close()
-
- return this.putReplicas(hash, t, expectedLength)
-}
-
-// Put a block given the block hash and a byte buffer. The desired number of
-// replicas is given in KeepClient.Want_replicas. Returns the number of
-// replicas that were written and if there was an error. Note this will return
-// InsufficientReplias whenever 0 <= replicas < this.Wants_replicas.
-func (this KeepClient) PutHB(hash string, buf []byte) (locator string, replicas int, err error) {
- t := streamer.AsyncStreamFromSlice(buf)
- defer t.Close()
-
- return this.putReplicas(hash, t, int64(len(buf)))
-}
-
-// Put a block given a buffer. The hash will be computed. The desired number
-// of replicas is given in KeepClient.Want_replicas. Returns the number of
-// replicas that were written and if there was an error. Note this will return
-// InsufficientReplias whenever 0 <= replicas < this.Wants_replicas.
-func (this KeepClient) PutB(buffer []byte) (locator string, replicas int, err error) {
- hash := fmt.Sprintf("%x", md5.Sum(buffer))
- return this.PutHB(hash, buffer)
-}
-
-// Put a block, given a Reader. This will read the entire reader into a buffer
-// to compute the hash. The desired number of replicas is given in
-// KeepClient.Want_replicas. Returns the number of replicas that were written
-// and if there was an error. Note this will return InsufficientReplias
-// whenever 0 <= replicas < this.Wants_replicas. Also nhote that if the block
-// hash and data size are available, PutHR() is more efficient.
-func (this KeepClient) PutR(r io.Reader) (locator string, replicas int, err error) {
- if buffer, err := ioutil.ReadAll(r); err != nil {
- return "", 0, err
- } else {
- return this.PutB(buffer)
- }
-}
-
-// Get a block given a hash. Return a reader, the expected data length, the
-// URL the block was fetched from, and if there was an error. If the block
-// checksum does not match, the final Read() on the reader returned by this
-// method will return a BadChecksum error instead of EOF.
-func (this KeepClient) Get(hash string) (reader io.ReadCloser,
- contentLength int64, url string, err error) {
- return this.AuthorizedGet(hash, "", "")
-}
-
-// Get a block given a hash, with additional authorization provided by
-// signature and timestamp. Return a reader, the expected data length, the URL
-// the block was fetched from, and if there was an error. If the block
-// checksum does not match, the final Read() on the reader returned by this
-// method will return a BadChecksum error instead of EOF.
-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.Arvados.ApiToken))
-
- var resp *http.Response
- if resp, err = this.Client.Do(req); err != nil {
- continue
- }
-
- if resp.StatusCode == http.StatusOK {
- return HashCheckingReader{resp.Body, md5.New(), hash}, resp.ContentLength, url, nil
- }
- }
-
- return nil, 0, "", BlockNotFound
-}
-
-// Determine if a block with the given hash is available and readable, but does
-// not return the block contents.
-func (this KeepClient) Ask(hash string) (contentLength int64, url string, err error) {
- return this.AuthorizedAsk(hash, "", "")
-}
-
-// Determine if a block with the given hash is available and readable with the
-// given signature and timestamp, but does not return the block contents.
-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.Arvados.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
-
-}
-
-// Atomically read the service_roots field.
-func (this *KeepClient) ServiceRoots() []string {
- r := (*[]string)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&this.service_roots))))
- return *r
-}
-
-// Atomically update the service_roots field. Enables you to update
-// service_roots without disrupting any GET or PUT operations that might
-// already be in progress.
-func (this *KeepClient) SetServiceRoots(svc []string) {
- // Must be sorted for ShuffledServiceRoots() to produce consistent
- // results.
- roots := make([]string, len(svc))
- copy(roots, svc)
- sort.Strings(roots)
- atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&this.service_roots)),
- unsafe.Pointer(&roots))
-}
-
-type Locator struct {
- Hash string
- Size int
- Signature string
- Timestamp string
-}
-
-func MakeLocator2(hash string, hints string) (locator Locator) {
- locator.Hash = hash
- if hints != "" {
- signature_pat, _ := regexp.Compile("^A([[:xdigit:]]+)@([[:xdigit:]]{8})$")
- for _, hint := range strings.Split(hints, "+") {
- if hint != "" {
- if match, _ := regexp.MatchString("^[[:digit:]]+$", hint); match {
- fmt.Sscanf(hint, "%d", &locator.Size)
- } else if m := signature_pat.FindStringSubmatch(hint); m != nil {
- locator.Signature = m[1]
- locator.Timestamp = m[2]
- } else if match, _ := regexp.MatchString("^[:upper:]", hint); match {
- // Any unknown hint that starts with an uppercase letter is
- // presumed to be valid and ignored, to permit forward compatibility.
- } else {
- // Unknown format; not a valid locator.
- return Locator{"", 0, "", ""}
- }
- }
- }
- }
- return locator
-}
-
-func MakeLocator(path string) Locator {
- pathpattern, err := regexp.Compile("^([0-9a-f]{32})([+].*)?$")
- if err != nil {
- log.Print("Don't like regexp", err)
- }
-
- sm := pathpattern.FindStringSubmatch(path)
- if sm == nil {
- log.Print("Failed match ", path)
- return Locator{"", 0, "", ""}
- }
-
- return MakeLocator2(sm[1], sm[2])
-}
projects / arvados.git / blobdiff
