github-migration/mongo-ruby-driver
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enabled keyf support for Collection#group

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This commit is contained in:
Kyle Banker 2009-12-18 14:48:44 -05:00
parent eaa12e2461
commit c15e8c2d7d
2 changed files with 91 additions and 64 deletions
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65
lib/mongo/collection.rb
View File

@ -339,9 +339,9 @@ module Mongo
# Performs a group query, similar to the 'SQL GROUP BY' operation.
# Returns an array of grouped items.
#
# :keys :: an array of fields to group by
# :condition :: specification of rows to be considered (as a 'find'
# query specification)
# :key :: either 1) an array of fields to group by, 2) a javascript function to generate
# the key object, or 3) nil.
# :condition :: an optional document specifying a query to limit the documents over which group is run.
# :initial :: initial value of the aggregation counter object
# :reduce :: aggregation function as a JavaScript string
# :finalize :: optional. a JavaScript function that receives and modifies
@ -350,26 +350,34 @@ module Mongo
# :command :: if true, run the group as a command instead of in an
# eval - it is likely that this option will eventually be
# deprecated and all groups will be run as commands
def group(keys, condition, initial, reduce, command=false, finalize=nil)
def group(key, condition, initial, reduce, command=false, finalize=nil)
if command
hash = {}
keys.each do |k|
hash[k] = 1
end
reduce = Code.new(reduce) unless reduce.is_a?(Code)
reduce = Code.new(reduce) unless reduce.is_a?(Code)
group_command = {
"group" => {
"ns" => @name,
"$reduce" => reduce,
"key" => hash,
"cond" => condition,
"initial" => initial
}
}
unless key.nil?
if key.is_a? Array
key_type = "key"
key_value = {}
key.each { |k| key_value[k] = 1 }
else
key_type = "$keyf"
key_value = key.is_a?(Code) ? key : Code.new(key)
end
group_command["group"][key_type] = key_value
end
# only add finalize if specified
if finalize
finalize = Code.new(finalize) unless finalize.is_a?(Code)
@ -383,22 +391,28 @@ module Mongo
else
raise OperationFailure, "group command failed: #{result['errmsg']}"
end
end
raise OperationFailure, ":finalize can be specified only when " +
"group is run as a command (set command param to true)" if finalize
case reduce
when Code
scope = reduce.scope
else
scope = {}
end
scope.merge!({
"ns" => @name,
"keys" => keys,
"condition" => condition,
"initial" => initial })
warn "Collection#group must now be run as a command; you can do this by passing 'true' as the command argument."
raise OperationFailure, ":finalize can be specified only when " +
"group is run as a command (set command param to true)" if finalize
raise OperationFailure, "key must be an array of fields to group by. If you want to pass a key function,
run group as a command by passing 'true' as the command argument." unless key.is_a? Array || key.nil?
case reduce
when Code
scope = reduce.scope
else
scope = {}
end
scope.merge!({
"ns" => @name,
"keys" => key,
"condition" => condition,
"initial" => initial })
group_function = <<EOS
function () {
@ -425,7 +439,8 @@ function () {
return {"result": map.values()};
}
EOS
@db.eval(Code.new(group_function, scope))["result"]
@db.eval(Code.new(group_function, scope))["result"]
end
end
# Returns a list of distinct values for +key+ across all

90
test/test_collection.rb
View File

@ -401,47 +401,59 @@ class TestCollection < Test::Unit::TestCase
assert_equal 1, x
end
def test_group_with_scope
@@test.save("a" => 1)
@@test.save("b" => 1)
reduce_function = "function (obj, prev) { prev.count += inc_value; }"
assert_equal 2, @@test.group([], {}, {"count" => 0},
Code.new(reduce_function,
{"inc_value" => 1}))[0]["count"]
# TODO enable these tests when SERVER-262 is fixed
# assert_equal 2, @@test.group([], {}, {"count" => 0},
# Code.new(reduce_function,
# {"inc_value" => 1}), true)[0]["count"]
assert_equal 4, @@test.group([], {}, {"count" => 0},
Code.new(reduce_function,
{"inc_value" => 2}))[0]["count"]
# assert_equal 4, @@test.group([], {}, {"count" => 0},
# Code.new(reduce_function,
# {"inc_value" => 2}), true)[0]["count"]
assert_equal 1, @@test.group([], {}, {"count" => 0},
Code.new(reduce_function,
{"inc_value" => 0.5}))[0]["count"]
# assert_equal 1, @@test.group([], {}, {"count" => 0},
# Code.new(reduce_function,
# {"inc_value" => 0.5}), true)[0]["count"]
# test finalize
#assert_equal( 3,
# @@test.group(
# [], {}, {"count" => 0},
# Code.new(reduce_function,{"inc_value" => 2}), true,
# Code.new("function (o) { o.final_count = o.count - 1; }")
# )[0]["final_count"]
#)
context "Grouping" do
setup do
@@test.remove
@@test.save("a" => 1)
@@test.save("b" => 1)
@initial = {"count" => 0}
@reduce_function = "function (obj, prev) { prev.count += inc_value; }"
end
should "group results using eval form" do
assert_equal 1, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 0.5}))[0]["count"]
assert_equal 2, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 1}))[0]["count"]
assert_equal 4, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 2}))[0]["count"]
end
should "group results using command form" do
assert_equal 1, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 0.5}), true)[0]["count"]
assert_equal 2, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 1}), true)[0]["count"]
assert_equal 4, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 2}), true)[0]["count"]
end
should "finalize grouped results" do
@finalize = "function(doc) {doc.f = doc.count + 200; }"
assert_equal 202, @@test.group([], {}, @initial, Code.new(@reduce_function, {"inc_value" => 1}), true, @finalize)[0]["f"]
end
end
context "Grouping with a key function" do
setup do
@@test.remove
@@test.save("a" => 1)
@@test.save("a" => 2)
@@test.save("a" => 3)
@@test.save("a" => 4)
@@test.save("a" => 5)
@initial = {"count" => 0}
@keyf = "function (doc) { if(doc.a % 2 == 0) { return {even: true}; } else {return {odd: true}} };"
@reduce = "function (obj, prev) { prev.count += 1; }"
end
should "group results" do
results = @@test.group(@keyf, {}, @initial, @reduce, true).sort {|a, b| a['count'] <=> b['count']}
assert results[0]['even'] && results[0]['count'] == 2.0
assert results[1]['odd'] && results[1]['count'] == 3.0
end
should "raise an error if trying to use keyf as a group eval" do
assert_raise OperationFailure do
@@test.group(@keyf, {}, @initial, @reduce)
end
end
end
context "A collection with two records" do
setup do
@collection = @@db.collection('test-collection')