taoensso.faraday — com.taoensso/faraday 1.10.0-alpha2

Clojure DynamoDB client. Originally adapted from Rotary by James Reeves. Ref. https://github.com/weavejester/rotary (Rotary), http://goo.gl/22QGA (DynamoDBv2 API)

Definitions:

• Attribute - [<name> <val>] pair
• Item - Collection of attributes
• Table - Collection of items
• Primary key - Partition (hash) key or Partition (hash) AND sort (range) key

*attr-multi-vs?* clj

Treat attribute vals as expansions rather than literals? nil => use attr-multi-vs?-default (currently true though this may be changed in future to better support DDB's new collection types, Ref. https://github.com/ptaoussanis/faraday/issues/63).

AsMap clj protocol

as-map clj

(as-map x)

batch-get-item clj

(batch-get-item client-opts
                requests
                &
                [{:keys [return-cc? span-reqs attr-multi-vs?]
                  :as opts
                  :or {span-reqs {:max 5}}}])

Retrieves a batch of items in a single request. Limits apply, Ref. http://goo.gl/Bj9TC.

(batch-get-item client-opts {:users {:prim-kvs {:name "alice"}} :posts {:prim-kvs {:id [1 2 3]} :attrs [:timestamp :subject] :consistent? true} :friends {:prim-kvs [{:catagory "favorites" :id [1 2 3]} {:catagory "recent" :id [7 8 9]}]}})

:span-reqs - {:max _ :throttle-ms _} allows a number of requests to automatically be stitched together (to exceed throughput limits, for example).

batch-write-item clj

(batch-write-item client-opts
                  requests
                  &
                  [{:keys [return-cc? span-reqs attr-multi-vs?]
                    :as opts
                    :or {span-reqs {:max 5}}}])

Executes a batch of Puts and/or Deletes in a single request. Limits apply, Ref. http://goo.gl/Bj9TC. No transaction guarantees are provided, nor conditional puts. Request execution order is undefined.

(batch-write-item client-opts {:users {:put [{:user-id 1 :username "sally"} {:user-id 2 :username "jane"}] :delete [{:user-id [3 4 5]}]}})

:span-reqs - {:max _ :throttle-ms _} allows a number of requests to automatically be stitched together (to exceed throughput limits, for example).

clj-item->db-item clj

create-table clj

(create-table client-opts
              table-name
              hash-keydef
              &
              [{:keys [range-keydef throughput lsindexes gsindexes block?]
                :as opts}])

Creates a table with options: hash-keydef - [<name> <#{:s :n :ss :ns :b :bs}>]. :range-keydef - [<name> <#{:s :n :ss :ns :b :bs}>]. :throughput - {:read <units> :write <units>}. :block? - Block for table to actually be active? :lsindexes - [{:name _ :range-keydef _ :projection <#{:all :keys-only [<attr> ...]}>}]. :gsindexes - [{:name _ :hash-keydef _ :range-keydef _ :projection <#{:all :keys-only [<attr> ...]}> :throughput _}]. :stream-spec - {:enabled? <default true if spec is present> :view-type <#{:keys-only :new-image :old-image :new-and-old-images}>}

db-item->clj-item clj

delete-item clj

(delete-item client-opts
             table
             prim-kvs
             &
             [{:keys [return expected return-cc?] :as opts}])

Deletes an item from a table by its primary key. See put-item for option docs.

delete-table clj

(delete-table client-opts table)

Deletes a table, go figure.

describe-stream clj

(describe-stream client-opts
                 stream-arn
                 &
                 [{:keys [limit start-shard-id] :as opts}])

Returns a map describing a stream, or nil if the stream doesn't exist.

describe-table clj

(describe-table client-opts table)

Returns a map describing a table, or nil if the table doesn't exist.

ensure-table clj

(ensure-table client-opts table-name hash-keydef & [opts])

Creates a table iff it doesn't already exist.

ex clj

DynamoDB API exceptions. Use #=(ex _) for try blocks, etc.

freeze clj

(freeze x)

(freeze x opts)

Forces argument of any type to be subject to automatic de/serialization with Nippy.

get-item clj

(get-item client-opts table prim-kvs & [opts])

Retrieves an item from a table by its primary key with options: prim-kvs - {<hash-key> <val>} or {<hash-key> <val> <range-key> <val>}. :attrs - Attrs to return, [<attr> ...]. :proj-expr - Projection expression as a string :expr-attr-names - Map of strings for ExpressionAttributeNames :consistent? - Use strongly (rather than eventually) consistent reads?

get-stream-records clj

(get-stream-records client-opts shard-iterator & [{:keys [limit] :as opts}])

ISerializable clj protocol

Extensible protocol for mapping Clojure vals to AttributeValue objects.

serialize clj

(serialize this)

items-by-attrs clj

(items-by-attrs attr-or-attrs item-or-items)

Groups one or more items by one or more attributes, returning a map of form {<attr-val> <item> ...} or {{<attr> <val> ...} <item>}.

Good for collecting batch or query/scan items results into useable maps, indexed by their 'primary key' (which, remember, may consist of 1 OR 2 attrs).

list-streams clj

(list-streams client-opts & [{:keys [start-arn table-name limit] :as opts}])

Returns a lazy sequence of stream descriptions. Each item is a map of: {:stream-arn - Stream identifier string :table-name - The table name for the stream}

Options: :start-arn - The stream identifier to start listing from (exclusive) :table-name - List only the streams for <table-name> :limit - Retrieve streams in batches of <limit> at a time

list-tables clj

(list-tables client-opts)

Returns a lazy sequence of table names.

put-item clj

(put-item client-opts
          table
          item
          &
          [{:keys [return expected return-cc? cond-expr] :as opts}])

Adds an item (Clojure map) to a table with options: :return - e/o #{:none :all-old} :cond-expr - "attribute_exists(attr_name) AND|OR ..." :expr-attr-names - {"#attr_name" "name"} :expr-attr-vals - {":attr_value" "value"} :expected - DEPRECATED in favor of :cond-expr, {<attr> <#{:exists :not-exists [<comparison-operator> <value>] <value>}> ...} With comparison-operator e/o #{:eq :le :lt :ge :gt :begins-with :between}.

query clj

(query client-opts
       table
       prim-key-conds
       &
       [{:keys [last-prim-kvs query-filter span-reqs return index order limit
                consistent? return-cc?]
         :as opts
         :or {span-reqs {:max 5}}}])

Retrieves items from a table (indexed) with options: prim-key-conds - {<key-attr> [<comparison-operator> <val-or-vals>] ...}. :last-prim-kvs - Primary key-val from which to eval, useful for paging. :query-filter - {<key-attr> [<comparison-operator> <val-or-vals>] ...}. :proj-expr - Projection expression string :filter-expr - Filter expression string :expr-attr-names - Expression attribute names, as a map of {"#attr_name" "name"} :expr-attr-vals - Expression attribute values, as a map {":attr_value" "value"} :span-reqs - {:max _ :throttle-ms _} controls automatic multi-request stitching. :return - e/o #{:all-attributes :all-projected-attributes :count [<attr> ...]}. :index - Name of a local or global secondary index to query. :order - Index scaning order e/o #{:asc :desc}. :limit - Max num >=1 of items to eval (≠ num of matching items). Useful to prevent harmful sudden bursts of read activity. :consistent? - Use strongly (rather than eventually) consistent reads?

(create-table client-opts :my-table [:name :s] {:range-keydef [:age :n] :block? true})

(do (put-item client-opts :my-table {:name "Steve" :age 24}) (put-item client-opts :my-table {:name "Susan" :age 27})) (query client-opts :my-table {:name [:eq "Steve"] :age [:between [10 30]]}) => [{:age 24, :name "Steve"}]

comparison-operators e/o #{:eq :le :lt :ge :gt :begins-with :between}.

For unindexed item retrievel see scan.

Ref. http://goo.gl/XfGKW for query+scan best practices.

remove-empty-attr-vals clj

Alpha, subject to change. Util to help remove (or coerce to nil) empty val types prohibited by DDB, Ref. http://goo.gl/Xg85pO. See also freeze as an alternative.

scan clj

(scan client-opts
      table
      &
      [{:keys [attr-conds last-prim-kvs span-reqs return limit total-segments
               filter-expr segment return-cc?]
        :as opts
        :or {span-reqs {:max 5}}}])

Retrieves items from a table (unindexed) with options: :attr-conds - {<attr> [<comparison-operator> <val-or-vals>] ...}. :expr-attr-names - Expression attribute names, as a map of {"#attr_name" "name"} :expr-attr-vals - Expression attribute names, as a map of {":attr" "value"} :filter-expr - Filter expression string :index - Index name to use. :proj-expr - Projection expression as a string :limit - Max num >=1 of items to eval (≠ num of matching items). Useful to prevent harmful sudden bursts of read activity. :last-prim-kvs - Primary key-val from which to eval, useful for paging. :span-reqs - {:max _ :throttle-ms _} controls automatic multi-request stitching. :return - e/o #{:all-attributes :all-projected-attributes :count [<attr> ...]}. :total-segments - Total number of parallel scan segments. :segment - Calling worker's segment number (>=0, <=total-segments). :consistent? - Use strongly (rather than eventually) consistent reads?

comparison-operators e/o #{:eq :le :lt :ge :gt :begins-with :between :ne :not-null :null :contains :not-contains :in}.

(create-table client-opts :my-table [:name :s] {:range-keydef [:age :n] :block? true})

(do (put-item client-opts :my-table {:name "Steve" :age 24}) (put-item client-opts :my-table {:name "Susan" :age 27})) (scan client-opts :my-table {:attr-conds {:age [:in [24 27]]}}) => [{:age 24, :name "Steve"} {:age 27, :name "Susan"}]

For automatic parallelization & segment control see scan-parallel. For indexed item retrievel see query.

Ref. http://goo.gl/XfGKW for query+scan best practices.

scan-parallel clj

(scan-parallel client-opts table total-segments & [opts])

Like scan but starts a number of worker threads and automatically handles parallel scan options (:total-segments and :segment). Returns a vector of scan results.

Ref. http://goo.gl/KLwnn (official parallel scan documentation).

shard-iterator clj

(shard-iterator client-opts
                stream-arn
                shard-id
                iterator-type
                &
                [{:keys [seq-num] :as opts}])

Returns the iterator string that can be used in the get-stream-records call or nil when the stream or shard doesn't exist.

update-item clj

(update-item client-opts
             table
             prim-kvs
             &
             [{:keys [update-map return expected return-cc? cond-expr
                      update-expr]
               :as opts}])

Updates an item in a table by its primary key with options: prim-kvs - {<hash-key> <val>} or {<hash-key> <val> <range-key> <val>} :update-map - DEPRECATED in favor of :update-expr, {<attr> [<#{:put :add :delete}> <optional value>]} :cond-expr - "attribute_exists(attr_name) AND|OR ..." :update-expr - "SET #attr_name = :attr_value" :expr-attr-names - {"#attr_name" "name"} :expr-attr-vals - {":attr_value" "value"} :return - e/o #{:none :all-old :updated-old :all-new :updated-new} :expected - DEPRECATED in favor of :cond-expr, {<attr> <#{:exists :not-exists [<comparison-operator> <value>] <value>}> ...} With comparison-operator e/o #{:eq :le :lt :ge :gt :begins-with :between}.

update-table clj

(update-table client-opts
              table
              update-opts
              &
              [{:keys [span-reqs] :or {span-reqs {:max 5}}}])

Returns a future which updates table and returns the post-update table description.

Update opts: :throughput - {:read <units> :write <units>} :gsindexes - {:operation ; e/o #{:create :update :delete} :name ; Required :throughput ; Only for :update / :create :hash-keydef ; Only for :create :range-keydef ; :projection ; e/o #{:all :keys-only [<attr> ...]}} :stream-spec - {:enabled? ; :view-type ; e/o #{:keys-only :new-image :old-image :old-and-new-images}}

Only one global secondary index operation can take place at a time. In order to change a stream view-type, you need to disable and re-enable the stream.

with-attr-multi-vs clj macro

(with-attr-multi-vs & body)

with-thaw-opts clj macro

(with-thaw-opts opts & body)

without-attr-multi-vs clj macro

(without-attr-multi-vs & body)