Module: CallCache

Defined in:
lib/cached_call.rb,
lib/call_cache.rb

Overview

Copyright 2007 Adam Wisniewski <[email protected]>

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at 

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Defined Under Namespace

Classes: CachedCall

Constant Summary collapse

CACHE_DIRECTORY = 
"/tmp/cache"
SECONDS_TO_CACHE = 
60 * 60 * 3

Class Method Summary collapse

Class Method Details

.call(function_call, hashes) ⇒ Object 



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# File 'lib/call_cache.rb', line 27

def CallCache.call( function_call, hashes )
    parameters = hashes[:pars]
    options = hashes[:options]
    
    ttl = SECONDS_TO_CACHE
    if !options.nil?
        if options[:ttl]
            ttl = options[:ttl]
        end
    end

    cached_call = CallCache.find( function_call, *parameters )
    
    if cached_call == nil || Time.now.to_i - cached_call.created_at.to_i > ttl
        return_val = CallCache.make_call( function_call, *parameters )
        cached_call = CachedCall.new( return_val, function_call, *parameters )
        
        CallCache.save( cached_call )
    end

    return cached_call.return_val          
end

.file_path_for(function_call, *parameters) ⇒ Object

def CallCache.check_or_create_tmp_dir

file_path = CallCache::CACHE_DIRECTORY + File::SEPARATOR + "call_cache_" + id_string

end



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# File 'lib/call_cache.rb', line 61

def CallCache.file_path_for( function_call, *parameters )
    CallCache::CACHE_DIRECTORY + File::SEPARATOR + 
                    "call_cache_" + CallCache.get_id_for( function_call, *parameters )
end

.find(function_call, *parameters) ⇒ Object 



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# File 'lib/call_cache.rb', line 66

def CallCache.find( function_call, *parameters )
    cached_call = nil

    file_path = CallCache.file_path_for(function_call, *parameters)

    if File.exist?( file_path )
        # return saved cached result
        cached_call = Marshal.load( File.read( file_path ) )
    end

    return cached_call
end

.get_id_for(function_call, *parameters) ⇒ Object 



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# File 'lib/call_cache.rb', line 50

def CallCache.get_id_for( function_call, *parameters)
    md5 = Digest::MD5::new
    md5.update( function_call.gsub('::', '_').gsub('.', '_') )
    md5.update( Marshal.dump( parameters ) )
    return md5.hexdigest   
end

.make_call(function_call, *parameters) ⇒ Object 



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# File 'lib/call_cache.rb', line 93

def CallCache.make_call( function_call, *parameters )
    # call function
    # parse call to handle local methods or static class methods 
    function_call.gsub!( '::', '.' )
    function_call_split = function_call.split(/\./)
    # make the call

    return_val = eval( function_call_split[0..-2].join('::') ).method( function_call_split[-1] ).call( *parameters )          

end

.save(cached_call) ⇒ Object 



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# File 'lib/call_cache.rb', line 79

def CallCache.save( cached_call )
    # write call to cache location

    if !File.directory?( CallCache::CACHE_DIRECTORY )
        Dir.mkdir( CallCache::CACHE_DIRECTORY )
    end

    file_path = CallCache.file_path_for( cached_call.function_call, *cached_call.parameters )
    dest_file = File.new( file_path, 'wb' )
    dest_file.write( Marshal.dump( cached_call ) )
    dest_file.close

end