Try to fix parallel fulfillment issues

calibre-plugin/__init__.py

@@ -99,6 +99,7 @@ __version__ = PLUGIN_VERSION = ".".join([str(x)for x in PLUGIN_VERSION_TUPLE])
 
 
 from calibre.utils.config import config_dir         # type: ignore
+from calibre.utils.lock import SingleInstance, singleinstance       # type: ignore
 
 import os, shutil, traceback, sys, time, io, random
 import zipfile
@@ -171,9 +172,10 @@ class ACSMInput(FileTypePlugin):
                 os.mkdir(self.pluginsdir)
 
             
-            # If the old DeACSM plugin still exists, rename it to BAK or something so it doesn't load.
+            if singleinstance("__acsm_rename_old_plugin"):
-            if os.path.exists(os.path.join(self.pluginsdir, "DeACSM.zip")):
+                # If the old DeACSM plugin still exists, rename it to BAK or something so it doesn't load.
-                os.rename(os.path.join(self.pluginsdir, "DeACSM.zip"), os.path.join(self.pluginsdir, "DeACSM.BAK"))
+                if os.path.exists(os.path.join(self.pluginsdir, "DeACSM.zip")):
+                    os.rename(os.path.join(self.pluginsdir, "DeACSM.zip"), os.path.join(self.pluginsdir, "DeACSM.BAK"))
                     
             
             try: 
@@ -237,55 +239,40 @@ class ACSMInput(FileTypePlugin):
                 print("Module update from \"{0}\" to \"{1}\", extracting ...".format(id, id_plugin))
                 # Something changed, extract modules.
 
+                if not singleinstance("__acsm_extracting modules"):
+                    print("Skipping because another instance is already doing that.")
+                else:
+                    if os.path.exists(self.moddir):
+                        shutil.rmtree(self.moddir, ignore_errors=True)
 
-                if os.path.exists(self.moddir):
+                    os.mkdir(self.moddir)
-                    shutil.rmtree(self.moddir, ignore_errors=True)
 
-                rand_path = self.moddir + str(random.randint(0, 1000000000))
+                    names = ["oscrypto.zip", "asn1crypto.zip"]
 
-                ctr = 0
+                    # oscrypto is needed to parse the pkcs12 data from Adobe.
-                while os.path.exists(rand_path):
+                    # asn1crypto is a dependency of oscrypto.
-                    # None of this code should be necessary since a random number between 0 and a billion should be unique
-                    # enough, but apparently not. Make new ones until we find one that's not in use.
-                    # Should be using Calibre's TemporaryFile class but then I can't be certain it's on the same drive...
-                    ctr += 1
-                    if (ctr > 1000):
-                        print("{0} v{1}: Tried a thousand times to get a temp dir ...".format(PLUGIN_NAME, PLUGIN_VERSION))
-                        raise Exception("Hey!")
                         
-                    rand_path = self.moddir + str(random.randint(0, 1000000000))
+                    lib_dict = self.load_resources(names)
 
-                os.mkdir(rand_path)
+                    for entry, data in lib_dict.items():
+                        try:
+                            with zipfile.ZipFile(io.BytesIO(data), 'r') as ref:
+                                ref.extractall(self.moddir)
 
-                names = ["oscrypto.zip", "asn1crypto.zip"]
+                        except:
-
+                            print("{0} v{1}: Exception when copying needed library files".format(PLUGIN_NAME, PLUGIN_VERSION))
-                # oscrypto is needed to parse the pkcs12 data from Adobe.
+                            traceback.print_exc()
-                # asn1crypto is a dependency of oscrypto.
+                            pass           
-                    
-                lib_dict = self.load_resources(names)
-
-                for entry, data in lib_dict.items():
-                    try:
-                        with zipfile.ZipFile(io.BytesIO(data), 'r') as ref:
-                            ref.extractall(rand_path)
-
-                    except:
-                        print("{0} v{1}: Exception when copying needed library files".format(PLUGIN_NAME, PLUGIN_VERSION))
-                        traceback.print_exc()
-                        pass           
 
 
-                # Write module ID
+                    # Write module ID
-                if id_plugin is not None: 
+                    if id_plugin is not None: 
-                    mod_file = os.path.join(rand_path, "module_id.txt")
+                        mod_file = os.path.join(self.moddir, "module_id.txt")
-                    f = open(mod_file, "w")
+                        f = open(mod_file, "w")
-                    f.write(id_plugin)
+                        f.write(id_plugin)
-                    f.close()
+                        f.close()
 
 
-                # Rename temporary path to actual module path so this will be used next time.
-                os.rename(rand_path, self.moddir)
-
             sys.path.insert(0, os.path.join(self.moddir, "oscrypto"))
             sys.path.insert(0, os.path.join(self.moddir, "asn1crypto"))
             
@@ -441,89 +428,62 @@ class ACSMInput(FileTypePlugin):
             print("{0} v{1}: Error: Unsupported file type ...".format(PLUGIN_NAME, PLUGIN_VERSION))
             return None
 
-    def is_blocked(self):
-        import calibre_plugins.deacsm.prefs as prefs     # type: ignore
-        deacsmprefs = prefs.ACSMInput_Prefs()
-        return deacsmprefs['fulfillment_block_token'] != 0
-    
-    def unblock(self):      
-        import calibre_plugins.deacsm.prefs as prefs     # type: ignore
-        deacsmprefs = prefs.ACSMInput_Prefs()
-
-        my_token = deacsmprefs["fulfillment_block_token"]
-        deacsmprefs.refresh()
-        if (my_token == deacsmprefs["fulfillment_block_token"]):
-            # Only unlock if this is my own lock
-
-            deacsmprefs.set("fulfillment_block_token", 0)
-            deacsmprefs.set("fulfillment_block_time", 0)
-            deacsmprefs.commit()
-
-
-    def wait_and_block(self):
-        random_identifier = None
-
-        import calibre_plugins.deacsm.prefs as prefs     # type: ignore
-        deacsmprefs = prefs.ACSMInput_Prefs()
-
-        while True: 
-            deacsmprefs.refresh()
-            if deacsmprefs["fulfillment_block_token"] == 0:
-                random_identifier = random.getrandbits(64)
-                #print("setting block token to %s" % (str(random_identifier)))
-                deacsmprefs.set("fulfillment_block_token", random_identifier)
-                deacsmprefs.commit()
-                deacsmprefs.refresh()
-                if random_identifier != deacsmprefs["fulfillment_block_token"]:
-                    # print("we broke another thread's global token")
-                    continue
-
-                deacsmprefs.set("fulfillment_block_time", int(time.time() * 1000))
-                #print("Obtained lock!")
-                return True
-            
-            else: 
-                # Token already exists, wait for it to finish ...
-                current_time = int(time.time() * 1000)
-                saved_time = deacsmprefs["fulfillment_block_time"]
-                if saved_time + 60000 < current_time:
-                    # Already locked since 60s, assume error
-                    print("{0} v{1}: Looks like the lock was stuck, removing lock {2} ...".format(PLUGIN_NAME, PLUGIN_VERSION, deacsmprefs["fulfillment_block_token"]))
-                    self.unblock()
-                
-                time.sleep(0.02)
-                continue
-
-
-
-
     def run(self, path_to_ebook):
         # type: (str) -> str
+
+
+        # This code gets called by Calibre with a path to the new book file. 
+
+        # Make sure there's only a single instance of this function running ever. 
+        # Calibre loves to run these in parallel when many ACSM files are being imported.
+        # However that A) messes with the loan records written to a file, and B) that behaviour
+        # is significantly different from ADE so Adobe could use that to detect this plugin. 
+        
+        # So, we're trying to use Calibre's singleinstance feature to prevent that. 
+
+
+        counter = 0
+        thread_id = -1
+
         try: 
-            # This code gets called by Calibre with a path to the new book file. 
+            import threading
+            thread_id = threading.current_thread().ident
+        except:
+            pass
+
+        while True:
+            with SingleInstance("__acsm_plugin_execute_run_acsm_file") as si:
+                if si:
+                    return self.run_single(path_to_ebook)
+                else:
+                    counter += 1
+                    if (counter % 100 == 0):
+                        print("Thread {0} still waiting for lock, attempt {1}".format(thread_id, counter))
+                    time.sleep(0.1)
+
+
+
+    def run_single(self, path_to_ebook):
+        # type: (str) -> str
+        try: 
+
             # We need to check if it's an ACSM file
 
             import calibre_plugins.deacsm.prefs as prefs     # type: ignore
             deacsmprefs = prefs.ACSMInput_Prefs()
 
-            if deacsmprefs['allow_parallel_fulfillment'] == False:
-                self.wait_and_block()
-
-
             print("{0} v{1}: Trying to parse file {2}".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
 
             ext = os.path.splitext(path_to_ebook)[1].lower()
 
             if (ext != ".acsm"):
                 print("{0} v{1}: That's not an ACSM, returning (is {2} instead)... ".format(PLUGIN_NAME, PLUGIN_VERSION, ext))
-                self.unblock()
                 return path_to_ebook
 
             # We would fulfill this now, but first perform some sanity checks ...
 
             if not self.ADE_sanity_check(): 
                 print("{0} v{1}: ADE auth is missing or broken ".format(PLUGIN_NAME, PLUGIN_VERSION))
-                self.unblock()
                 return path_to_ebook
 
 
@@ -532,7 +492,6 @@ class ACSMInput(FileTypePlugin):
 
             if not are_ade_version_lists_valid():
                 print("{0} v{1}: ADE version list mismatch, please open a bug report.".format(PLUGIN_NAME, PLUGIN_VERSION))
-                self.unblock()
                 return path_to_ebook
 
             print("{0} v{1}: Try to fulfill ...".format(PLUGIN_NAME, PLUGIN_VERSION))
@@ -643,13 +602,10 @@ class ACSMInput(FileTypePlugin):
                     
                     
                     # Return path - either the original one or the one modified by the other plugins.
-                    self.unblock()
                     return rpl
 
-            self.unblock()
             return path_to_ebook
         except: 
-            self.unblock()
             traceback.print_exc()
             return path_to_ebook
         

calibre-plugin/config.py

@@ -64,7 +64,6 @@ class ConfigWidget(QWidget):
         self.tempdeacsmprefs['notify_fulfillment'] = self.deacsmprefs['notify_fulfillment']
         self.tempdeacsmprefs['detailed_logging'] = self.deacsmprefs['detailed_logging']
         self.tempdeacsmprefs['delete_acsm_after_fulfill'] = self.deacsmprefs['delete_acsm_after_fulfill']
-        self.tempdeacsmprefs['allow_parallel_fulfillment'] = self.deacsmprefs['allow_parallel_fulfillment']
 
         self.tempdeacsmprefs['list_of_rented_books'] = self.deacsmprefs['list_of_rented_books']
 
@@ -186,10 +185,6 @@ class ConfigWidget(QWidget):
         self.chkDeleteAfterFulfill.toggled.connect(self.toggle_acsm_delete)
         layout.addWidget(self.chkDeleteAfterFulfill)
 
-        self.chkParallelFulfill = QtGui.QCheckBox("Allow parallel fulfillment")
-        self.chkParallelFulfill.setToolTip("Default: True\n\nIf this is enabled (which was the default in previous versions), \nthe plugin will import multiple ACSM files simultaneously when you add more than one.\n\nIf this is disabled, it will add them one after another like ADE.")
-        self.chkParallelFulfill.setChecked(self.tempdeacsmprefs["allow_parallel_fulfillment"])
-        layout.addWidget(self.chkParallelFulfill)
 
         # Key shortcut Ctrl+Shift+D / Cmd+Shift+D to remove authorization, just like in ADE.
         self.deauthShortcut = QShortcut(QKeySequence("Ctrl+Shift+D"), self)
@@ -1284,7 +1279,6 @@ class ConfigWidget(QWidget):
         self.deacsmprefs.set('notify_fulfillment', self.chkNotifyFulfillment.isChecked())
         self.deacsmprefs.set('detailed_logging', self.chkDetailedLogging.isChecked())
         self.deacsmprefs.set('delete_acsm_after_fulfill', self.chkDeleteAfterFulfill.isChecked())
-        self.deacsmprefs.set('allow_parallel_fulfillment', self.chkParallelFulfill.isChecked())
         self.deacsmprefs.writeprefs()
 
     def load_resource(self, name):

calibre-plugin/libadobeFulfill.py

@@ -581,77 +581,24 @@ def addLoanRecordToConfigFile(new_loan_record):
         return False
 
 
-    error_counter = 0
+    # Check if that exact loan is already in the list, and if so, delete it:
-    last_token = None
+    done = False
-    random_identifier = None
+    while not done:
-
+        done = True
-    while True: 
+        for book in deacsmprefs["list_of_rented_books"]:
-
+            if book["loanID"] == new_loan_record["loanID"]:
-        if error_counter >= 10: 
+                done = False
-            print("Took us 10 attempts to acquire loan token lock, still didn't work.")
+                deacsmprefs["list_of_rented_books"].remove(book)
-            print("(still the same token %s)" % (deacsmprefs["loan_identifier_token"]))
+                break
-            print("If you see this error message please open a bug report.")
 
 
-        # "Mark" the current access with a random token, to prevent multiple instances
+    # Add all necessary information for a book return to the JSON array.
-        # of the plugin overwriting eachother's data.
+    # The config widget can then read this and present a list of not-yet-returned
-        deacsmprefs.refresh()
+    # books, and can then return them.
-        if deacsmprefs["loan_identifier_token"] == 0: 
+    # Also, the config widget is responsible for cleaning up that list once a book's validity period is up.
-            random_identifier = random.getrandbits(64)
+    deacsmprefs["list_of_rented_books"].append(new_loan_record)
-            deacsmprefs.set("loan_identifier_token", random_identifier)
-            deacsmprefs.commit()
-            deacsmprefs.refresh()
-            if random_identifier != deacsmprefs["loan_identifier_token"]:
-                #print("we broke another thread's token, try again")
-                last_token = deacsmprefs["loan_identifier_token"]
-                error_counter = error_counter + 1
-                continue
-        else: 
-            if last_token != deacsmprefs["loan_identifier_token"]:
-                #print("Token changed in the meantime ...")
-                # Give it another 5 tries
-                error_counter = max(0, error_counter - 5)
-                pass
 
-            last_token = deacsmprefs["loan_identifier_token"]
+    return True
-            #print("waiting on another thread ...")
-            sleeptime = random.randrange(2, 10) / 1000
-            print(str(sleeptime))
-            time.sleep(sleeptime)
-            error_counter = error_counter + 1
-            continue
-
-        # Okay, now this thread can "use" the config list, and no other thread should overwrite it ...        
-        # Check if that exact loan is already in the list, and if so, delete it:
-        done = False
-        while not done:
-            done = True
-            for book in deacsmprefs["list_of_rented_books"]:
-                if book["loanID"] == new_loan_record["loanID"]:
-                    done = False
-                    deacsmprefs["list_of_rented_books"].remove(book)
-                    break
-
-
-        # Add all necessary information for a book return to the JSON array.
-        # The config widget can then read this and present a list of not-yet-returned
-        # books, and can then return them.
-        # Also, the config widget is responsible for cleaning up that list once a book's validity period is up.
-        deacsmprefs["list_of_rented_books"].append(new_loan_record)
-
-        # Okay, now we added our loan record. 
-        # Remove the identifier token so other threads can use the config again: 
-        deacsmprefs.commit()
-        deacsmprefs.refresh()
-        if deacsmprefs["loan_identifier_token"] != random_identifier:
-            print("Another thread stole the loan token while we were working with it - that's not supposed to happen ...")
-            print("If you see this message, please open a bug report.")
-            return False
-
-        deacsmprefs.set("loan_identifier_token", 0)
-        deacsmprefs.commit()
-
-        return True
 
 
 def tryReturnBook(bookData): 

calibre-plugin/prefs.py

@@ -35,12 +35,6 @@ class ACSMInput_Prefs():
         self.deacsmprefs.defaults['notify_fulfillment'] = True
         self.deacsmprefs.defaults['detailed_logging'] = False
         self.deacsmprefs.defaults['delete_acsm_after_fulfill'] = False
-        self.deacsmprefs.defaults['allow_parallel_fulfillment'] = True
-
-        self.deacsmprefs.defaults['loan_identifier_token'] = 0
-        self.deacsmprefs.defaults['fulfillment_block_token'] = 0
-        self.deacsmprefs.defaults['fulfillment_block_time'] = 0
-
 
         self.deacsmprefs.defaults['list_of_rented_books'] = []