+/* PullHandler processes "PUT /pull" requests for the data manager.
+ The request body is a JSON message containing a list of pull
+ requests in the following format:
+
+ [
+ {
+ "locator":"e4d909c290d0fb1ca068ffaddf22cbd0+4985",
+ "servers":[
+ "keep0.qr1hi.arvadosapi.com:25107",
+ "keep1.qr1hi.arvadosapi.com:25108"
+ ]
+ },
+ {
+ "locator":"55ae4d45d2db0793d53f03e805f656e5+658395",
+ "servers":[
+ "10.0.1.5:25107",
+ "10.0.1.6:25107",
+ "10.0.1.7:25108"
+ ]
+ },
+ ...
+ ]
+
+ Each pull request in the list consists of a block locator string
+ and an ordered list of servers. Keepstore should try to fetch the
+ block from each server in turn.
+
+ If the request has not been sent by the Data Manager, return 401
+ Unauthorized.
+
+ If the JSON unmarshalling fails, return 400 Bad Request.
+*/
+
+type PullRequest struct {
+ Locator string `json:"locator"`
+ Servers []string `json:"servers"`
+}
+
+func PullHandler(resp http.ResponseWriter, req *http.Request) {
+ // Reject unauthorized requests.
+ if !IsDataManagerToken(GetApiToken(req)) {
+ http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
+ log.Printf("%s %s: %s\n", req.Method, req.URL, UnauthorizedError.Error())
+ return
+ }
+
+ // Parse the request body.
+ var pr []PullRequest
+ r := json.NewDecoder(req.Body)
+ if err := r.Decode(&pr); err != nil {
+ http.Error(resp, BadRequestError.Error(), BadRequestError.HTTPCode)
+ log.Printf("%s %s: %s\n", req.Method, req.URL, err.Error())
+ return
+ }
+
+ // We have a properly formatted pull list sent from the data
+ // manager. Report success and send the list to the pull list
+ // manager for further handling.
+ log.Printf("%s %s: received %v\n", req.Method, req.URL, pr)
+ resp.WriteHeader(http.StatusOK)
+ resp.Write([]byte(
+ fmt.Sprintf("Received %d pull requests\n", len(pr))))
+
+ plist := list.New()
+ for _, p := range pr {
+ plist.PushBack(p)
+ }
+
+ if pullq == nil {
+ pullq = NewWorkQueue()
+ }
+ pullq.ReplaceQueue(plist)
+}
+
+type TrashRequest struct {
+ Locator string `json:"locator"`
+ BlockMtime int64 `json:"block_mtime"`
+}
+
+func TrashHandler(resp http.ResponseWriter, req *http.Request) {
+ // Reject unauthorized requests.
+ if !IsDataManagerToken(GetApiToken(req)) {
+ http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
+ log.Printf("%s %s: %s\n", req.Method, req.URL, UnauthorizedError.Error())
+ return
+ }
+
+ // Parse the request body.
+ var trash []TrashRequest
+ r := json.NewDecoder(req.Body)
+ if err := r.Decode(&trash); err != nil {
+ http.Error(resp, BadRequestError.Error(), BadRequestError.HTTPCode)
+ log.Printf("%s %s: %s\n", req.Method, req.URL, err.Error())
+ return
+ }
+
+ // We have a properly formatted trash list sent from the data
+ // manager. Report success and send the list to the trash work
+ // queue for further handling.
+ log.Printf("%s %s: received %v\n", req.Method, req.URL, trash)
+ resp.WriteHeader(http.StatusOK)
+ resp.Write([]byte(
+ fmt.Sprintf("Received %d trash requests\n", len(trash))))
+
+ tlist := list.New()
+ for _, t := range trash {
+ tlist.PushBack(t)
+ }
+
+ if trashq == nil {
+ trashq = NewWorkQueue()
+ }
+ trashq.ReplaceQueue(tlist)
+}
+
+// ==============================
+// GetBlock and PutBlock implement lower-level code for handling
+// blocks by rooting through volumes connected to the local machine.
+// Once the handler has determined that system policy permits the
+// request, it calls these methods to perform the actual operation.
+//
+// TODO(twp): this code would probably be better located in the
+// VolumeManager interface. As an abstraction, the VolumeManager
+// should be the only part of the code that cares about which volume a
+// block is stored on, so it should be responsible for figuring out
+// which volume to check for fetching blocks, storing blocks, etc.
+
+// ==============================
+// GetBlock fetches and returns the block identified by "hash". If
+// the update_timestamp argument is true, GetBlock also updates the
+// block's file modification time (for the sake of PutBlock, which
+// must update the file's timestamp when the block already exists).
+//
+// On success, GetBlock returns a byte slice with the block data, and
+// a nil error.
+//
+// If the block cannot be found on any volume, returns NotFoundError.
+//
+// If the block found does not have the correct MD5 hash, returns
+// DiskHashError.
+//
+
+func GetBlock(hash string, update_timestamp bool) ([]byte, error) {