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amazonka-dynamodb-streams-2.0: gen/Amazonka/DynamoDBStreams/GetShardIterator.hs

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_GHC -fno-warn-unused-binds #-}
{-# OPTIONS_GHC -fno-warn-unused-imports #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}

-- Derived from AWS service descriptions, licensed under Apache 2.0.

-- |
-- Module      : Amazonka.DynamoDBStreams.GetShardIterator
-- Copyright   : (c) 2013-2023 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
--
-- Returns a shard iterator. A shard iterator provides information about
-- how to retrieve the stream records from within a shard. Use the shard
-- iterator in a subsequent @GetRecords@ request to read the stream records
-- from the shard.
--
-- A shard iterator expires 15 minutes after it is returned to the
-- requester.
module Amazonka.DynamoDBStreams.GetShardIterator
  ( -- * Creating a Request
    GetShardIterator (..),
    newGetShardIterator,

    -- * Request Lenses
    getShardIterator_sequenceNumber,
    getShardIterator_streamArn,
    getShardIterator_shardId,
    getShardIterator_shardIteratorType,

    -- * Destructuring the Response
    GetShardIteratorResponse (..),
    newGetShardIteratorResponse,

    -- * Response Lenses
    getShardIteratorResponse_shardIterator,
    getShardIteratorResponse_httpStatus,
  )
where

import qualified Amazonka.Core as Core
import qualified Amazonka.Core.Lens.Internal as Lens
import qualified Amazonka.Data as Data
import Amazonka.DynamoDBStreams.Types
import qualified Amazonka.Prelude as Prelude
import qualified Amazonka.Request as Request
import qualified Amazonka.Response as Response

-- | Represents the input of a @GetShardIterator@ operation.
--
-- /See:/ 'newGetShardIterator' smart constructor.
data GetShardIterator = GetShardIterator'
  { -- | The sequence number of a stream record in the shard from which to start
    -- reading.
    sequenceNumber :: Prelude.Maybe Prelude.Text,
    -- | The Amazon Resource Name (ARN) for the stream.
    streamArn :: Prelude.Text,
    -- | The identifier of the shard. The iterator will be returned for this
    -- shard ID.
    shardId :: Prelude.Text,
    -- | Determines how the shard iterator is used to start reading stream
    -- records from the shard:
    --
    -- -   @AT_SEQUENCE_NUMBER@ - Start reading exactly from the position
    --     denoted by a specific sequence number.
    --
    -- -   @AFTER_SEQUENCE_NUMBER@ - Start reading right after the position
    --     denoted by a specific sequence number.
    --
    -- -   @TRIM_HORIZON@ - Start reading at the last (untrimmed) stream
    --     record, which is the oldest record in the shard. In DynamoDB
    --     Streams, there is a 24 hour limit on data retention. Stream records
    --     whose age exceeds this limit are subject to removal (trimming) from
    --     the stream.
    --
    -- -   @LATEST@ - Start reading just after the most recent stream record in
    --     the shard, so that you always read the most recent data in the
    --     shard.
    shardIteratorType :: ShardIteratorType
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'GetShardIterator' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'sequenceNumber', 'getShardIterator_sequenceNumber' - The sequence number of a stream record in the shard from which to start
-- reading.
--
-- 'streamArn', 'getShardIterator_streamArn' - The Amazon Resource Name (ARN) for the stream.
--
-- 'shardId', 'getShardIterator_shardId' - The identifier of the shard. The iterator will be returned for this
-- shard ID.
--
-- 'shardIteratorType', 'getShardIterator_shardIteratorType' - Determines how the shard iterator is used to start reading stream
-- records from the shard:
--
-- -   @AT_SEQUENCE_NUMBER@ - Start reading exactly from the position
--     denoted by a specific sequence number.
--
-- -   @AFTER_SEQUENCE_NUMBER@ - Start reading right after the position
--     denoted by a specific sequence number.
--
-- -   @TRIM_HORIZON@ - Start reading at the last (untrimmed) stream
--     record, which is the oldest record in the shard. In DynamoDB
--     Streams, there is a 24 hour limit on data retention. Stream records
--     whose age exceeds this limit are subject to removal (trimming) from
--     the stream.
--
-- -   @LATEST@ - Start reading just after the most recent stream record in
--     the shard, so that you always read the most recent data in the
--     shard.
newGetShardIterator ::
  -- | 'streamArn'
  Prelude.Text ->
  -- | 'shardId'
  Prelude.Text ->
  -- | 'shardIteratorType'
  ShardIteratorType ->
  GetShardIterator
newGetShardIterator
  pStreamArn_
  pShardId_
  pShardIteratorType_ =
    GetShardIterator'
      { sequenceNumber = Prelude.Nothing,
        streamArn = pStreamArn_,
        shardId = pShardId_,
        shardIteratorType = pShardIteratorType_
      }

-- | The sequence number of a stream record in the shard from which to start
-- reading.
getShardIterator_sequenceNumber :: Lens.Lens' GetShardIterator (Prelude.Maybe Prelude.Text)
getShardIterator_sequenceNumber = Lens.lens (\GetShardIterator' {sequenceNumber} -> sequenceNumber) (\s@GetShardIterator' {} a -> s {sequenceNumber = a} :: GetShardIterator)

-- | The Amazon Resource Name (ARN) for the stream.
getShardIterator_streamArn :: Lens.Lens' GetShardIterator Prelude.Text
getShardIterator_streamArn = Lens.lens (\GetShardIterator' {streamArn} -> streamArn) (\s@GetShardIterator' {} a -> s {streamArn = a} :: GetShardIterator)

-- | The identifier of the shard. The iterator will be returned for this
-- shard ID.
getShardIterator_shardId :: Lens.Lens' GetShardIterator Prelude.Text
getShardIterator_shardId = Lens.lens (\GetShardIterator' {shardId} -> shardId) (\s@GetShardIterator' {} a -> s {shardId = a} :: GetShardIterator)

-- | Determines how the shard iterator is used to start reading stream
-- records from the shard:
--
-- -   @AT_SEQUENCE_NUMBER@ - Start reading exactly from the position
--     denoted by a specific sequence number.
--
-- -   @AFTER_SEQUENCE_NUMBER@ - Start reading right after the position
--     denoted by a specific sequence number.
--
-- -   @TRIM_HORIZON@ - Start reading at the last (untrimmed) stream
--     record, which is the oldest record in the shard. In DynamoDB
--     Streams, there is a 24 hour limit on data retention. Stream records
--     whose age exceeds this limit are subject to removal (trimming) from
--     the stream.
--
-- -   @LATEST@ - Start reading just after the most recent stream record in
--     the shard, so that you always read the most recent data in the
--     shard.
getShardIterator_shardIteratorType :: Lens.Lens' GetShardIterator ShardIteratorType
getShardIterator_shardIteratorType = Lens.lens (\GetShardIterator' {shardIteratorType} -> shardIteratorType) (\s@GetShardIterator' {} a -> s {shardIteratorType = a} :: GetShardIterator)

instance Core.AWSRequest GetShardIterator where
  type
    AWSResponse GetShardIterator =
      GetShardIteratorResponse
  request overrides =
    Request.postJSON (overrides defaultService)
  response =
    Response.receiveJSON
      ( \s h x ->
          GetShardIteratorResponse'
            Prelude.<$> (x Data..?> "ShardIterator")
            Prelude.<*> (Prelude.pure (Prelude.fromEnum s))
      )

instance Prelude.Hashable GetShardIterator where
  hashWithSalt _salt GetShardIterator' {..} =
    _salt
      `Prelude.hashWithSalt` sequenceNumber
      `Prelude.hashWithSalt` streamArn
      `Prelude.hashWithSalt` shardId
      `Prelude.hashWithSalt` shardIteratorType

instance Prelude.NFData GetShardIterator where
  rnf GetShardIterator' {..} =
    Prelude.rnf sequenceNumber
      `Prelude.seq` Prelude.rnf streamArn
      `Prelude.seq` Prelude.rnf shardId
      `Prelude.seq` Prelude.rnf shardIteratorType

instance Data.ToHeaders GetShardIterator where
  toHeaders =
    Prelude.const
      ( Prelude.mconcat
          [ "X-Amz-Target"
              Data.=# ( "DynamoDBStreams_20120810.GetShardIterator" ::
                          Prelude.ByteString
                      ),
            "Content-Type"
              Data.=# ( "application/x-amz-json-1.0" ::
                          Prelude.ByteString
                      )
          ]
      )

instance Data.ToJSON GetShardIterator where
  toJSON GetShardIterator' {..} =
    Data.object
      ( Prelude.catMaybes
          [ ("SequenceNumber" Data..=)
              Prelude.<$> sequenceNumber,
            Prelude.Just ("StreamArn" Data..= streamArn),
            Prelude.Just ("ShardId" Data..= shardId),
            Prelude.Just
              ("ShardIteratorType" Data..= shardIteratorType)
          ]
      )

instance Data.ToPath GetShardIterator where
  toPath = Prelude.const "/"

instance Data.ToQuery GetShardIterator where
  toQuery = Prelude.const Prelude.mempty

-- | Represents the output of a @GetShardIterator@ operation.
--
-- /See:/ 'newGetShardIteratorResponse' smart constructor.
data GetShardIteratorResponse = GetShardIteratorResponse'
  { -- | The position in the shard from which to start reading stream records
    -- sequentially. A shard iterator specifies this position using the
    -- sequence number of a stream record in a shard.
    shardIterator :: Prelude.Maybe Prelude.Text,
    -- | The response's http status code.
    httpStatus :: Prelude.Int
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'GetShardIteratorResponse' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'shardIterator', 'getShardIteratorResponse_shardIterator' - The position in the shard from which to start reading stream records
-- sequentially. A shard iterator specifies this position using the
-- sequence number of a stream record in a shard.
--
-- 'httpStatus', 'getShardIteratorResponse_httpStatus' - The response's http status code.
newGetShardIteratorResponse ::
  -- | 'httpStatus'
  Prelude.Int ->
  GetShardIteratorResponse
newGetShardIteratorResponse pHttpStatus_ =
  GetShardIteratorResponse'
    { shardIterator =
        Prelude.Nothing,
      httpStatus = pHttpStatus_
    }

-- | The position in the shard from which to start reading stream records
-- sequentially. A shard iterator specifies this position using the
-- sequence number of a stream record in a shard.
getShardIteratorResponse_shardIterator :: Lens.Lens' GetShardIteratorResponse (Prelude.Maybe Prelude.Text)
getShardIteratorResponse_shardIterator = Lens.lens (\GetShardIteratorResponse' {shardIterator} -> shardIterator) (\s@GetShardIteratorResponse' {} a -> s {shardIterator = a} :: GetShardIteratorResponse)

-- | The response's http status code.
getShardIteratorResponse_httpStatus :: Lens.Lens' GetShardIteratorResponse Prelude.Int
getShardIteratorResponse_httpStatus = Lens.lens (\GetShardIteratorResponse' {httpStatus} -> httpStatus) (\s@GetShardIteratorResponse' {} a -> s {httpStatus = a} :: GetShardIteratorResponse)

instance Prelude.NFData GetShardIteratorResponse where
  rnf GetShardIteratorResponse' {..} =
    Prelude.rnf shardIterator
      `Prelude.seq` Prelude.rnf httpStatus