Class: Thingfish::Metastore::Memory

Inherits:
Thingfish::Metastore show all
Extended by:
Loggability
Includes:
Normalization
Defined in:
lib/thingfish/metastore/memory.rb

Overview

An in-memory metastore for testing and tryout purposes.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Normalization

make_object_id, normalize_key, normalize_keys, normalize_oid

Methods inherited from Thingfish::Metastore

#inspect, #transaction

Constructor Details

#initialize(storage = {}) ⇒ Memory

Create a new MemoryMetastore, using the given storage object to store data in. The storage should quack like a Hash.



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# File 'lib/thingfish/metastore/memory.rb', line 20

def initialize( storage={} )
  @storage = storage
end

Instance Attribute Details

#storage ⇒ Object (readonly)

The raw Hash of metadata



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# File 'lib/thingfish/metastore/memory.rb', line 27

def storage
  @storage
end

Instance Method Details

#apply_search_criteria(ds, options) ⇒ Object

Apply the search :criteria from the specified options to the collection in ds and return the modified dataset.



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# File 'lib/thingfish/metastore/memory.rb', line 114

def apply_search_criteria( ds, options )
  if (( criteria = options[:criteria] ))
    criteria.each do |field, value|
      self.log.debug "  applying criteria: %p => %p" % [ field.to_s, value ]
      ds = ds.select {|uuid| @storage[uuid][field.to_s] == value }
    end
  end

  return ds
end

#apply_search_direction(ds, options) ⇒ Object

Apply the search :direction from the specified options to the collection in ds and return the modified dataset.



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# File 'lib/thingfish/metastore/memory.rb', line 141

def apply_search_direction( ds, options )
  ds.reverse! if options[:direction] && options[:direction] == 'desc'
  return ds
end

#apply_search_limit(ds, options) ⇒ Object

Apply the search :limit from the specified options to the collection in ds and return the modified dataset.



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# File 'lib/thingfish/metastore/memory.rb', line 149

def apply_search_limit( ds, options )
  if (( limit = options[:limit] ))
    self.log.debug "  limiting to %s results" % [ limit ]
    offset = options[:offset] || 0
    ds = ds.to_a.slice( offset, limit )
  end

  return ds
end

#apply_search_order(ds, options) ⇒ Object

Apply the search :order from the specified options to the collection in ds and return the modified dataset.



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# File 'lib/thingfish/metastore/memory.rb', line 128

def apply_search_order( ds, options )
  if (( fields = options[:order] ))
    ds = ds.to_a.sort_by do |uuid|
      @storage[ uuid ].values_at( *fields.compact ).map {|val| val || ''}
    end
  end

  return ds
end

#each_oid(&block) ⇒ Object

Iterate over the OID of each entry in the store, yielding to the block if one is given or returning an Enumerator if one is not.



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# File 'lib/thingfish/metastore/memory.rb', line 38

def each_oid( &block )
  return @storage.each_key( &block )
end

#fetch(oid, *keys) ⇒ Object

Fetch the data corresponding to the given oid as a Hash-ish object.



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# File 'lib/thingfish/metastore/memory.rb', line 51

def fetch( oid, *keys )
  oid = normalize_oid( oid )
  metadata = @storage[ oid ] or return nil

  if keys.empty?
    self.log.debug "Fetching metadata for OID %s" % [ oid ]
    return metadata.dup
  else
    self.log.debug "Fetching metadata for %p for OID %s" % [ keys, oid ]
    keys = normalize_keys( keys )
    values = metadata.values_at( *keys )
    return Hash[ [keys, values].transpose ]
  end
end

#fetch_related_oids(oid) ⇒ Object

Fetch OIDs related to the given oid.



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# File 'lib/thingfish/metastore/memory.rb', line 79

def fetch_related_oids( oid )
  oid = normalize_oid( oid )
  self.log.debug "Fetching OIDs of resources related to %s" % [ oid ]
  return self.search( :criteria => {:relation => oid}, :include_related => true )
end

#fetch_value(oid, key) ⇒ Object

Fetch the value of the metadata associated with the given key for the specified oid.



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# File 'lib/thingfish/metastore/memory.rb', line 69

def fetch_value( oid, key )
  oid = normalize_oid( oid )
  key = normalize_key( key )
  data = @storage[ oid ] or return nil

  return data[ key ]
end

#include?(oid) ⇒ Boolean

Returns true if the metastore has metadata associated with the specified oid.

Returns:

  • (Boolean) 


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# File 'lib/thingfish/metastore/memory.rb', line 189

def include?( oid )
  oid = normalize_oid( oid )
  return @storage.include?( oid )
end

#merge(oid, values) ⇒ Object

Update the metadata for the given oid with the specified values hash.



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# File 'lib/thingfish/metastore/memory.rb', line 161

def merge( oid, values )
  oid = normalize_oid( oid )
  values = normalize_keys( values )
  @storage[ oid ].merge!( values )
end

#oids ⇒ Object

Return an Array of all stored OIDs.



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# File 'lib/thingfish/metastore/memory.rb', line 31

def oids
  return @storage.keys
end

#omit_related_resources(ds, options) ⇒ Object

Omit related resources from the search dataset ds unless the given options specify otherwise.



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# File 'lib/thingfish/metastore/memory.rb', line 104

def omit_related_resources( ds, options )
  unless options[:include_related]
    ds = ds.reject {|uuid| @storage[uuid]['relationship'] }
  end
  return ds
end

#remove(oid, *keys) ⇒ Object

Remove all metadata associated with oid from the Metastore.



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# File 'lib/thingfish/metastore/memory.rb', line 169

def remove( oid, *keys )
  oid = normalize_oid( oid )
  if keys.empty?
    @storage.delete( oid )
  else
    keys = normalize_keys( keys )
    @storage[ oid ].delete_if {|key, _| keys.include?(key) }
  end
end

#remove_except(oid, *keys) ⇒ Object

Remove all metadata associated with oid except for the specified keys.



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# File 'lib/thingfish/metastore/memory.rb', line 181

def remove_except( oid, *keys )
  oid = normalize_oid( oid )
  keys = normalize_keys( keys )
  @storage[ oid ].keep_if {|key,_| keys.include?(key) }
end

#save(oid, metadata) ⇒ Object

Save the metadata Hash for the specified oid.



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# File 'lib/thingfish/metastore/memory.rb', line 44

def save( oid, metadata )
  oid = normalize_oid( oid )
  @storage[ oid ] = metadata.dup
end

#search(options = {}) ⇒ Object

Search the metastore for UUIDs which match the specified criteria and return them as an iterator.



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# File 'lib/thingfish/metastore/memory.rb', line 88

def search( options={} )
  ds = @storage.each_key
  self.log.debug "Starting search with %p" % [ ds ]

  ds = self.omit_related_resources( ds, options )
  ds = self.apply_search_criteria( ds, options )
  ds = self.apply_search_order( ds, options )
  ds = self.apply_search_direction( ds, options )
  ds = self.apply_search_limit( ds, options )

  return ds.to_a
end

#size ⇒ Object

Returns the number of objects the store contains.



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# File 'lib/thingfish/metastore/memory.rb', line 196

def size
  return @storage.size
end