WIP caching

Gopkg.toml

@@ -101,3 +101,7 @@
 
 [[constraint]]
   name = "gopkg.in/yaml.v2"
+
+[[constraint]]
+  branch = "master"
+  name = "github.com/gregjones/httpcache"

README.md

@@ -161,10 +161,10 @@ COPY bin/my-wag-service /usr/bin/my-wag-service
       * Must be a simple or array type. If an array must be an array of strings
       * If the type is 'simple' and the parameter is not required, the type will be a pointer
       * If the type is 'array' it won't be a pointer. Query parameters can't distinguish between an empty array and an nil array so it converts both these cases to a nil array. If you need to distinguish between the two use a body parameter
-      * In other cases the parameter is not a pointer 
+      * In other cases the parameter is not a pointer
     * Header parameters
       * Must be simple types
-      * If marked required will ensure that the input isn't the nil value. Headers cannot have pointer types since HTTP doesn't distinguish between empty and missing headers. 
+      * If marked required will ensure that the input isn't the nil value. Headers cannot have pointer types since HTTP doesn't distinguish between empty and missing headers.
       * If it doesn't have a default value specified, the default value will be the nil value for the type
 
 ### Paging
@@ -191,6 +191,20 @@ COPY bin/my-wag-service /usr/bin/my-wag-service
     that exposes `map`, `forEach`, and `toArray` functions to iterate over the
     results, again requesting new pages as needed.
 
+### Caching
+  * Wag can add `max-age` cache-control headers on respones if you use the `x-caching`
+    configuration:
+    ```
+  /bookscached/{id}:
+    get:
+      operationId: getBookByIDCached
+      x-caching:
+        max-age: 3600
+    ```
+  * Wag clients have a `SetCache` method to enable caching of responses. `SetCache`
+    takes a single argument, which is an interface that defines a mechanism for storing
+    cached response data.
+
 ### Contexts
   * The first argument to every Wag function is a `context.Context` (https://blog.golang.org/context). Contexts play a few important roles in Wag.
     * They can be used to set request specific behavior like a retry policy in client libraries. This includes timeouts and cancellation.
@@ -203,7 +217,7 @@ COPY bin/my-wag-service /usr/bin/my-wag-service
 
   * If you don't have a context to pass to a Wag function you have two options
     * context.Background() - use this when this is the creator of the request chain, like a test or a top-level service.
-    * context.TODO() - use this when you haven't been passed a context from a caller yet, but you expect the caller to send you one at some point.  
+    * context.TODO() - use this when you haven't been passed a context from a caller yet, but you expect the caller to send you one at some point.
 
 
 ### Tracing

clients/go/gengo.go

@@ -38,13 +38,15 @@ import (
 		"strconv"
 		"encoding/json"
 		"strconv"
+		"sync/atomic"
 		"time"
 		"fmt"
 		"crypto/md5"
 
 		"{{.PackageName}}/models"
 		discovery "github.com/Clever/discovery-go"
 		"github.com/afex/hystrix-go/hystrix"
+		"github.com/gregjones/httpcache"
 		logger "gopkg.in/Clever/kayvee-go.v6/logger"
 )
 
@@ -57,7 +59,7 @@ var _ = bytes.Compare
 type WagClient struct {
 	basePath    string
 	requestDoer doer
-	transport   *http.Transport
+	transport   http.RoundTripper
 	timeout     time.Duration
 	// Keep the retry doer around so that we can set the number of retries
 	retryDoer *retryDoer
@@ -111,6 +113,47 @@ func NewFromDiscovery() (*WagClient, error) {
 	return New(url), nil
 }
 
+func newCacheHitCounter(cache httpcache.Cache, basePath string, l logger.KayveeLogger) *cacheHitCounter {
+	chc := &cacheHitCounter{Cache: cache, basePath: basePath}
+	go chc.log(l)
+	return chc
+}
+
+type cacheHitCounter struct {
+	httpcache.Cache
+	hits     int64
+	misses   int64
+	basePath string
+}
+
+func (c *cacheHitCounter) log(l logger.KayveeLogger) {
+	ticker := time.NewTicker(time.Second * 30)
+	for _ = range ticker.C {
+		hits := atomic.LoadInt64(&c.hits)
+		misses := atomic.LoadInt64(&c.misses)
+		l.InfoD("wag-cache-stats", map[string]interface{}{
+			"hits":   hits,
+			"misses": misses,
+			"url":    c.basePath,
+		})
+	}
+}
+
+func (c *cacheHitCounter) Get(key string) ([]byte, bool) {
+	resp, ok := c.Cache.Get(key)
+	if ok {
+		atomic.AddInt64(&c.hits, 1)
+	} else {
+		atomic.AddInt64(&c.misses, 1)
+	}
+	return resp, ok
+}
+
+// SetCache enables caching.
+func (c *WagClient) SetCache(cache httpcache.Cache) {
+	c.transport = httpcache.NewTransport(newCacheHitCounter(cache, c.basePath, c.logger))
+}
+
 // SetRetryPolicy sets a the given retry policy for all requests.
 func (c *WagClient) SetRetryPolicy(retryPolicy RetryPolicy) {
 	c.retryDoer.retryPolicy = retryPolicy

samples/gen-go-deprecated/client/client.go

@@ -9,11 +9,13 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	discovery "github.com/Clever/discovery-go"
 	"github.com/Clever/wag/samples/gen-go-deprecated/models"
 	"github.com/afex/hystrix-go/hystrix"
+	"github.com/gregjones/httpcache"
 	logger "gopkg.in/Clever/kayvee-go.v6/logger"
 )
 
@@ -26,7 +28,7 @@ var _ = bytes.Compare
 type WagClient struct {
 	basePath    string
 	requestDoer doer
-	transport   *http.Transport
+	transport   http.RoundTripper
 	timeout     time.Duration
 	// Keep the retry doer around so that we can set the number of retries
 	retryDoer *retryDoer
@@ -80,6 +82,47 @@ func NewFromDiscovery() (*WagClient, error) {
 	return New(url), nil
 }
 
+func newCacheHitCounter(cache httpcache.Cache, basePath string, l logger.KayveeLogger) *cacheHitCounter {
+	chc := &cacheHitCounter{Cache: cache, basePath: basePath}
+	go chc.log(l)
+	return chc
+}
+
+type cacheHitCounter struct {
+	httpcache.Cache
+	hits     int64
+	misses   int64
+	basePath string
+}
+
+func (c *cacheHitCounter) log(l logger.KayveeLogger) {
+	ticker := time.NewTicker(time.Second * 30)
+	for _ = range ticker.C {
+		hits := atomic.LoadInt64(&c.hits)
+		misses := atomic.LoadInt64(&c.misses)
+		l.InfoD("wag-cache-stats", map[string]interface{}{
+			"hits":   hits,
+			"misses": misses,
+			"url":    c.basePath,
+		})
+	}
+}
+
+func (c *cacheHitCounter) Get(key string) ([]byte, bool) {
+	resp, ok := c.Cache.Get(key)
+	if ok {
+		atomic.AddInt64(&c.hits, 1)
+	} else {
+		atomic.AddInt64(&c.misses, 1)
+	}
+	return resp, ok
+}
+
+// SetCache enables caching.
+func (c *WagClient) SetCache(cache httpcache.Cache) {
+	c.transport = httpcache.NewTransport(newCacheHitCounter(cache, c.basePath, c.logger))
+}
+
 // SetRetryPolicy sets a the given retry policy for all requests.
 func (c *WagClient) SetRetryPolicy(retryPolicy RetryPolicy) {
 	c.retryDoer.retryPolicy = retryPolicy

samples/gen-go-deprecated/models/bad_request.go

@@ -1,5 +1,3 @@
-// Code generated by go-swagger; DO NOT EDIT.
-
 package models
 
 // This file was generated by the swagger tool.
@@ -9,20 +7,16 @@ import (
 	strfmt "github.com/go-openapi/strfmt"
 
 	"github.com/go-openapi/errors"
-	"github.com/go-openapi/swag"
 )
 
 // BadRequest bad request
 // swagger:model BadRequest
-
 type BadRequest struct {
 
 	// message
 	Message string `json:"message,omitempty"`
 }
 
-/* polymorph BadRequest message false */
-
 // Validate validates this bad request
 func (m *BadRequest) Validate(formats strfmt.Registry) error {
 	var res []error
@@ -32,21 +26,3 @@ func (m *BadRequest) Validate(formats strfmt.Registry) error {
 	}
 	return nil
 }
-
-// MarshalBinary interface implementation
-func (m *BadRequest) MarshalBinary() ([]byte, error) {
-	if m == nil {
-		return nil, nil
-	}
-	return swag.WriteJSON(m)
-}
-
-// UnmarshalBinary interface implementation
-func (m *BadRequest) UnmarshalBinary(b []byte) error {
-	var res BadRequest
-	if err := swag.ReadJSON(b, &res); err != nil {
-		return err
-	}
-	*m = res
-	return nil
-}

samples/gen-go-deprecated/models/internal_error.go

@@ -1,5 +1,3 @@
-// Code generated by go-swagger; DO NOT EDIT.
-
 package models
 
 // This file was generated by the swagger tool.
@@ -9,20 +7,16 @@ import (
 	strfmt "github.com/go-openapi/strfmt"
 
 	"github.com/go-openapi/errors"
-	"github.com/go-openapi/swag"
 )
 
 // InternalError internal error
 // swagger:model InternalError
-
 type InternalError struct {
 
 	// message
 	Message string `json:"message,omitempty"`
 }
 
-/* polymorph InternalError message false */
-
 // Validate validates this internal error
 func (m *InternalError) Validate(formats strfmt.Registry) error {
 	var res []error
@@ -32,21 +26,3 @@ func (m *InternalError) Validate(formats strfmt.Registry) error {
 	}
 	return nil
 }
-
-// MarshalBinary interface implementation
-func (m *InternalError) MarshalBinary() ([]byte, error) {
-	if m == nil {
-		return nil, nil
-	}
-	return swag.WriteJSON(m)
-}
-
-// UnmarshalBinary interface implementation
-func (m *InternalError) UnmarshalBinary(b []byte) error {
-	var res InternalError
-	if err := swag.ReadJSON(b, &res); err != nil {
-		return err
-	}
-	*m = res
-	return nil
-}

samples/gen-go-deprecated/models/not_found.go

@@ -1,5 +1,3 @@
-// Code generated by go-swagger; DO NOT EDIT.
-
 package models
 
 // This file was generated by the swagger tool.
@@ -9,20 +7,16 @@ import (
 	strfmt "github.com/go-openapi/strfmt"
 
 	"github.com/go-openapi/errors"
-	"github.com/go-openapi/swag"
 )
 
 // NotFound not found
 // swagger:model NotFound
-
 type NotFound struct {
 
 	// message
 	Message string `json:"message,omitempty"`
 }
 
-/* polymorph NotFound message false */
-
 // Validate validates this not found
 func (m *NotFound) Validate(formats strfmt.Registry) error {
 	var res []error
@@ -32,21 +26,3 @@ func (m *NotFound) Validate(formats strfmt.Registry) error {
 	}
 	return nil
 }
-
-// MarshalBinary interface implementation
-func (m *NotFound) MarshalBinary() ([]byte, error) {
-	if m == nil {
-		return nil, nil
-	}
-	return swag.WriteJSON(m)
-}
-
-// UnmarshalBinary interface implementation
-func (m *NotFound) UnmarshalBinary(b []byte) error {
-	var res NotFound
-	if err := swag.ReadJSON(b, &res); err != nil {
-		return err
-	}
-	*m = res
-	return nil
-}