Pseudo code for KVS written, ready to be coded up

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Browse code Pseudo code for KVS written, ready to be coded up master
1 parent c8841cc commit f7996a9231b5cea591124d56f799c4a466d9d5e2 David Whale authored on 26 May 2016

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          59 ■■■■■
          doc/devices_classes_branch.txt
 --------------------------------------------------------------------------------
TODO NEXT
 
KVS - key value store
 
first line is a command, next lines are data, type is the class to instantiate,
other parameters passed as kwargs. Pass parameter as string, constructor
recognizes hex inside string and base16 parses it to an int first. If no 0x,
it parses as base 10. Record terminated by blank line or EOF.
Multiple blank lines ignored. # at start of command line ignores the whole rec,
allowing user to comment it out temporarily
 
ADD tv
type=ENER005
device_id=0x68b
 
First parse is read only open scan of whole file
 
If user calls del kvs["tv"]
file opened in read write
first instance of 'tv' found
ADD command changed to IGN (ignore) (same number of chars, so no file size change)
file closed
 
When the parser processes it next time, the IGN command just skips
everything until blank line or EOF.
 
 
---- PERSISTENT REGISTRY
 
* choose a file format for the registry that is human readable like a config file
  but also easy to read and occasionally write from a program
 
  Remember that when restoring the registry in a new run, it can
  be told to auto-create device object variables.
 
contents (to allow auto creation)
  key: user assigned name
  values: fsk or ook selector (others in the future)
          address(mfrid, productid, deviceid)
          date/time added to registry?
 
If the user creates a wrapping class around this, we won't store that.
Also no device state will be persisted, it's just a registry of devices
with enough info to auto-create variables for each, correctly bound to
the right device class instances and the correct incoming message router
and outgoing message encoder/modulator.
 
implement and test code (write a test harness)
 
---- NOTIFY, UPDATE, or DATA SEQUENCE?
 
Consider whether there is a need for a general update notify
 --------------------------------------------------------------------------------
 TODO NEXT
 KVS - key value store
-first line is a command, next lines are data, type is the class to instantiate,
-other parameters passed as kwargs. Pass parameter as string, constructor
-recognizes hex inside string and base16 parses it to an int first. If no 0x,
-it parses as base 10. Record terminated by blank line or EOF.
-Multiple blank lines ignored. # at start of command line ignores the whole rec,
-allowing user to comment it out temporarily
-ADD tv
-type=ENER005
-device_id=0x68b
-First parse is read only open scan of whole file
-If user calls del kvs["tv"]
-file opened in read write
-first instance of 'tv' found
-ADD command changed to IGN (ignore) (same number of chars, so no file size change)
-file closed
-When the parser processes it next time, the IGN command just skips
-everything until blank line or EOF.
 ---- PERSISTENT REGISTRY
+* choose a file format for the registry that is human readable like a config file
+  but also easy to read and occasionally write from a program
+  Remember that when restoring the registry in a new run, it can
+  be told to auto-create device object variables.
+contents (to allow auto creation)
+  key: user assigned name
+  values: fsk or ook selector (others in the future)
+          address(mfrid, productid, deviceid)
+          date/time added to registry?
+If the user creates a wrapping class around this, we won't store that.
+Also no device state will be persisted, it's just a registry of devices
+with enough info to auto-create variables for each, correctly bound to
+the right device class instances and the correct incoming message router
+and outgoing message encoder/modulator.
+implement and test code (write a test harness)
 ---- NOTIFY, UPDATE, or DATA SEQUENCE?
 Consider whether there is a need for a general update notify

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          114 ■■■■■
          src/energenie/Registry.py
 def get_info(sensor_id):
    return directory[sensor_id]
 
 
#----- GENERIC KEY VALUE STORE ------------------------------------------------
 
class KVS():
    DEFAULT_FILENAME='registry.kvs'
 
    def __init__(self, filename=None, context=None):
        if filename == None: filename = KVS.DEFAULT_FILENAME
        # context is the namespace consulted to get class variables from when creating objects
        self.context = context
        self.store = {}
 
    def load(self):
        """Load the whole file into an in-memory cache"""
        pass #TODO
        # open file for read
        # for each line read
        #   if in command mode
        #       if blank line, ignore it
        #       else not blank line
        #           split line, first word is command, second word is the key
        #           remember both
        #           change to data mode
        #   else in data mode
        #       if not blank line
        #           grab key=value
        #           add to temporary object
        #       else blank line
        #           process command,key,values
        # now eof
        #   process command,key,values, if it command is not empty
        # close file
 
    def process(self, command, key, values):
        """Process the temporary object"""
        pass #TODO
        # getattr method associated with the command name, error if no method
        # pass the key,values to that method to let it be processed
 
    def ADD(self, key, values):
        """Add a new item to the kvs"""
        # The ADD command process the next type= parameter as the class name in context
        # all other parameters are read as strings and passed to class constructor as kwargs
        pass #TODO
        # add key=values to the in memory object store
        # open file for append
        # write ADD command with key
        # for all keys in value
        #   write k=v
        # close file
 
    def IGN(self, key, values=None):
        """Ignore the whole record"""
        # The IGN command is the same length as ADD, allowing a seek/write to change any
        # command into IGN without changing the file size, effectively patching the file
        # so that the record is deleted.
        pass # There is nothing to do with this command
 
    def DEL(self, key, values=None):
        """Delete the key from the store"""
        # The DEL command deletes the rec from the store.
        # This is useful to build temporary objects and delete them later.
        # There is no need to write this to the file copy, we're processing the file
        pass #TODO
        # find key in object store, delete it
 
    def __getattr__(self, key):
        return self.store[key]
 
    def __setattr__(self, key, value):
        self.store[key] = value
        self.append(key, value)
 
    def __delitem__(self, key):
        del self.store[key]
        self.remove(key)
 
    def append(self, key, values):
        """Append a new record to the persistent file"""
        pass #TODO
        # open file for append
        # write ADD key
        # for all values
        #   write k=v
        # close file
 
    def remove(self, key):
        """Remove reference to this key in the file, and remove from in memory store"""
        pass #TODO
        # open file for read write
        # search line at a time, process each command
        #   when we find the command 'ADD key'
        #   reseek to start of line
        #   write overwrite ADD with IGN
        #   keep going in case of duplicates
        # close file
 
    def rewrite(self):
        """Rewrite the whole in memory cache over the top of the external file"""
        # useful if you have updated the in memory copy only and want to completely regenerate
        pass #TODO
        # create file new, for write only
        # for all objects in the store by key
        #   get value
        #   write ADD command key
        #   for all values
        #       write k=v
        #   write blank line
        # close file
 
 
#----- NEW DEVICE REGISTRY ----------------------------------------------------
 
 
 
 
 
 
# Done as a class, so we can have multiple registries if we want.
 
# TODO: file format? platform dependent database format, like dbm but there is
 def get_info(sensor_id):
     return directory[sensor_id]
+#----- GENERIC KEY VALUE STORE ------------------------------------------------
+class KVS():
+    DEFAULT_FILENAME='registry.kvs'
+    def __init__(self, filename=None, context=None):
+        if filename == None: filename = KVS.DEFAULT_FILENAME
+        # context is the namespace consulted to get class variables from when creating objects
+        self.context = context
+        self.store = {}
+    def load(self):
+        """Load the whole file into an in-memory cache"""
+        pass #TODO
+        # open file for read
+        # for each line read
+        #   if in command mode
+        #       if blank line, ignore it
+        #       else not blank line
+        #           split line, first word is command, second word is the key
+        #           remember both
+        #           change to data mode
+        #   else in data mode
+        #       if not blank line
+        #           grab key=value
+        #           add to temporary object
+        #       else blank line
+        #           process command,key,values
+        # now eof
+        #   process command,key,values, if it command is not empty
+        # close file
+    def process(self, command, key, values):
+        """Process the temporary object"""
+        pass #TODO
+        # getattr method associated with the command name, error if no method
+        # pass the key,values to that method to let it be processed
+    def ADD(self, key, values):
+        """Add a new item to the kvs"""
+        # The ADD command process the next type= parameter as the class name in context
+        # all other parameters are read as strings and passed to class constructor as kwargs
+        pass #TODO
+        # add key=values to the in memory object store
+        # open file for append
+        # write ADD command with key
+        # for all keys in value
+        #   write k=v
+        # close file
+    def IGN(self, key, values=None):
+        """Ignore the whole record"""
+        # The IGN command is the same length as ADD, allowing a seek/write to change any
+        # command into IGN without changing the file size, effectively patching the file
+        # so that the record is deleted.
+        pass # There is nothing to do with this command
+    def DEL(self, key, values=None):
+        """Delete the key from the store"""
+        # The DEL command deletes the rec from the store.
+        # This is useful to build temporary objects and delete them later.
+        # There is no need to write this to the file copy, we're processing the file
+        pass #TODO
+        # find key in object store, delete it
+    def __getattr__(self, key):
+        return self.store[key]
+    def __setattr__(self, key, value):
+        self.store[key] = value
+        self.append(key, value)
+    def __delitem__(self, key):
+        del self.store[key]
+        self.remove(key)
+    def append(self, key, values):
+        """Append a new record to the persistent file"""
+        pass #TODO
+        # open file for append
+        # write ADD key
+        # for all values
+        #   write k=v
+        # close file
+    def remove(self, key):
+        """Remove reference to this key in the file, and remove from in memory store"""
+        pass #TODO
+        # open file for read write
+        # search line at a time, process each command
+        #   when we find the command 'ADD key'
+        #   reseek to start of line
+        #   write overwrite ADD with IGN
+        #   keep going in case of duplicates
+        # close file
+    def rewrite(self):
+        """Rewrite the whole in memory cache over the top of the external file"""
+        # useful if you have updated the in memory copy only and want to completely regenerate
+        pass #TODO
+        # create file new, for write only
+        # for all objects in the store by key
+        #   get value
+        #   write ADD command key
+        #   for all values
+        #       write k=v
+        #   write blank line
+        # close file
 #----- NEW DEVICE REGISTRY ----------------------------------------------------
 # Done as a class, so we can have multiple registries if we want.
 # TODO: file format? platform dependent database format, like dbm but there is

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