add dynamo

Signed-off-by: Taylor Skinner <tskinn12@gmail.com>

add some comments

Signed-off-by: Taylor Skinner <tskinn12@gmail.com>

update readmes

make test runnable

Signed-off-by: Taylor Skinner <tskinn12@gmail.com>

make test

squash! add dynamo

add glide.lock

format imports

gofmt

update glide.lock

fixes for review

golint

clean up and reorganize tests

add dynamodb integration test

remove default region. clean up tests. consistent docs

forgot the region is required

DRY

make validate

update readme and commit dependencies

vendor/github.com/aws/aws-sdk-go/service/dynamodb/customizations.go

@@ -0,0 +1,98 @@
+package dynamodb
+
+import (
+	"bytes"
+	"hash/crc32"
+	"io"
+	"io/ioutil"
+	"math"
+	"strconv"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	"github.com/aws/aws-sdk-go/aws/client"
+	"github.com/aws/aws-sdk-go/aws/request"
+)
+
+type retryer struct {
+	client.DefaultRetryer
+}
+
+func (d retryer) RetryRules(r *request.Request) time.Duration {
+	delay := time.Duration(math.Pow(2, float64(r.RetryCount))) * 50
+	return delay * time.Millisecond
+}
+
+func init() {
+	initClient = func(c *client.Client) {
+		r := retryer{}
+		if c.Config.MaxRetries == nil || aws.IntValue(c.Config.MaxRetries) == aws.UseServiceDefaultRetries {
+			r.NumMaxRetries = 10
+		} else {
+			r.NumMaxRetries = *c.Config.MaxRetries
+		}
+		c.Retryer = r
+
+		c.Handlers.Build.PushBack(disableCompression)
+		c.Handlers.Unmarshal.PushFront(validateCRC32)
+	}
+}
+
+func drainBody(b io.ReadCloser, length int64) (out *bytes.Buffer, err error) {
+	if length < 0 {
+		length = 0
+	}
+	buf := bytes.NewBuffer(make([]byte, 0, length))
+
+	if _, err = buf.ReadFrom(b); err != nil {
+		return nil, err
+	}
+	if err = b.Close(); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func disableCompression(r *request.Request) {
+	r.HTTPRequest.Header.Set("Accept-Encoding", "identity")
+}
+
+func validateCRC32(r *request.Request) {
+	if r.Error != nil {
+		return // already have an error, no need to verify CRC
+	}
+
+	// Checksum validation is off, skip
+	if aws.BoolValue(r.Config.DisableComputeChecksums) {
+		return
+	}
+
+	// Try to get CRC from response
+	header := r.HTTPResponse.Header.Get("X-Amz-Crc32")
+	if header == "" {
+		return // No header, skip
+	}
+
+	expected, err := strconv.ParseUint(header, 10, 32)
+	if err != nil {
+		return // Could not determine CRC value, skip
+	}
+
+	buf, err := drainBody(r.HTTPResponse.Body, r.HTTPResponse.ContentLength)
+	if err != nil { // failed to read the response body, skip
+		return
+	}
+
+	// Reset body for subsequent reads
+	r.HTTPResponse.Body = ioutil.NopCloser(bytes.NewReader(buf.Bytes()))
+
+	// Compute the CRC checksum
+	crc := crc32.ChecksumIEEE(buf.Bytes())
+
+	if crc != uint32(expected) {
+		// CRC does not match, set a retryable error
+		r.Retryable = aws.Bool(true)
+		r.Error = awserr.New("CRC32CheckFailed", "CRC32 integrity check failed", nil)
+	}
+}