Merge pull request #26 from fastly/fgsch/rework-limits

Rework limits

Author: fgsch

_examples/limits/main.go

@@ -0,0 +1,19 @@
+// Copyright 2023 Fastly, Inc.
+
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/fastly/compute-sdk-go/fsthttp"
+)
+
+func main() {
+	// Increase URL length limit to 16K
+	fsthttp.RequestLimits.SetMaxURLLen(16 * 1024)
+
+	fsthttp.ServeFunc(func(ctx context.Context, w fsthttp.ResponseWriter, r *fsthttp.Request) {
+		fmt.Fprintf(w, "The length of the URL is %d\n", len(r.URL.String()))
+	})
+}

fsthttp/limits.go

@@ -1,49 +1,49 @@
 package fsthttp
 
-import "github.com/fastly/compute-sdk-go/internal/abi/fastly"
-
 // Limits handles HTTP limits
-var Limits = limits{}
-
-type limits struct {
+type Limits struct {
+	maxHeaderNameLen  int
+	maxHeaderValueLen int
+	maxMethodLen      int
+	maxURLLen         int
 }
 
 // MaxHeaderNameLen gets the header name limit
-func (limits) MaxHeaderNameLen() int {
-	return fastly.MaxHeaderNameLen
+func (limits *Limits) MaxHeaderNameLen() int {
+	return limits.maxHeaderNameLen
 }
 
 // SetMaxHeaderNameLen sets the header name limit
-func (limits) SetMaxHeaderNameLen(len int) {
-	fastly.MaxHeaderNameLen = len
+func (limits *Limits) SetMaxHeaderNameLen(len int) {
+	limits.maxHeaderNameLen = len
 }
 
 // MaxHeaderValueLen gets the header value limit
-func (limits) MaxHeaderValueLen() int {
-	return fastly.MaxHeaderValueLen
+func (limits *Limits) MaxHeaderValueLen() int {
+	return limits.maxHeaderValueLen
 }
 
 // SetMaxHeaderValueLen sets the header value limit
-func (limits) SetMaxHeaderValueLen(len int) {
-	fastly.MaxHeaderValueLen = len
+func (limits *Limits) SetMaxHeaderValueLen(len int) {
+	limits.maxHeaderValueLen = len
 }
 
 // MaxMethodLen gets the request method limit
-func (limits) MaxMethodLen() int {
-	return fastly.MaxMethodLen
+func (limits *Limits) MaxMethodLen() int {
+	return limits.maxMethodLen
 }
 
 // SetMaxMethodLen sets the request method limit
-func (limits) SetMaxMethodLen(len int) {
-	fastly.MaxMethodLen = len
+func (limits *Limits) SetMaxMethodLen(len int) {
+	limits.maxMethodLen = len
 }
 
 // MaxURLLen gets the request URL limit
-func (limits) MaxURLLen() int {
-	return fastly.MaxURLLen
+func (limits *Limits) MaxURLLen() int {
+	return limits.maxURLLen
 }
 
 // SetMaxURLLen sets the request URL limit
-func (limits) SetMaxURLLen(len int) {
-	fastly.MaxURLLen = len
+func (limits *Limits) SetMaxURLLen(len int) {
+	limits.maxURLLen = len
 }

fsthttp/request.go

@@ -13,6 +13,14 @@ import (
 	"github.com/fastly/compute-sdk-go/internal/abi/fastly"
 )
 
+// RequestLimits are the limits for the components of an HTTP request.
+var RequestLimits = Limits{
+	maxHeaderNameLen:  fastly.DefaultMaxHeaderNameLen,
+	maxHeaderValueLen: fastly.DefaultMaxHeaderValueLen,
+	maxMethodLen:      fastly.DefaultMaxMethodLen,
+	maxURLLen:         fastly.DefaultMaxURLLen,
+}
+
 // Request represents an HTTP request received by this server from a requesting
 // client, or to be sent from this server during this execution. Some fields
 // only have meaning in one context or the other.
@@ -116,12 +124,12 @@ func newClientRequest() (*Request, error) {
 		return nil, fmt.Errorf("get client request and body: %w", err)
 	}
 
-	method, err := abiReq.GetMethod()
+	method, err := abiReq.GetMethod(RequestLimits.maxMethodLen)
 	if err != nil {
 		return nil, fmt.Errorf("get method: %w", err)
 	}
 
-	uri, err := abiReq.GetURI()
+	uri, err := abiReq.GetURI(RequestLimits.maxURLLen)
 	if err != nil {
 		return nil, fmt.Errorf("get URI: %w", err)
 	}
@@ -137,10 +145,10 @@ func newClientRequest() (*Request, error) {
 	}
 
 	header := NewHeader()
-	keys := abiReq.GetHeaderNames()
+	keys := abiReq.GetHeaderNames(RequestLimits.maxHeaderNameLen)
 	for keys.Next() {
 		k := string(keys.Bytes())
-		vals := abiReq.GetHeaderValues(k)
+		vals := abiReq.GetHeaderValues(k, RequestLimits.maxHeaderValueLen)
 		for vals.Next() {
 			v := string(vals.Bytes())
 			header.Add(k, v)

fsthttp/response.go

@@ -10,6 +10,12 @@ import (
 	"github.com/fastly/compute-sdk-go/internal/abi/fastly"
 )
 
+// ResponseLimits are the limits for the components of an HTTP response.
+var ResponseLimits = Limits{
+	maxHeaderNameLen:  fastly.DefaultMaxHeaderNameLen,
+	maxHeaderValueLen: fastly.DefaultMaxHeaderValueLen,
+}
+
 // Response to an outgoing HTTP request made by this server.
 type Response struct {
 	// Request associated with the response.
@@ -40,10 +46,10 @@ func newResponse(req *Request, backend string, abiResp *fastly.HTTPResponse, abi
 	}
 
 	header := NewHeader()
-	keys := abiResp.GetHeaderNames()
+	keys := abiResp.GetHeaderNames(ResponseLimits.maxHeaderNameLen)
 	for keys.Next() {
 		k := string(keys.Bytes())
-		vals := abiResp.GetHeaderValues(k)
+		vals := abiResp.GetHeaderValues(k, ResponseLimits.maxHeaderValueLen)
 		for vals.Next() {
 			v := string(vals.Bytes())
 			header.Add(k, v)

internal/abi/fastly/hostcalls_guest.go

@@ -668,7 +668,7 @@ func fastlyHTTPReqHeaderNamesGet(
 
 // GetHeaderNames returns an iterator that yields the names of each header of
 // the request.
-func (r *HTTPRequest) GetHeaderNames() *Values {
+func (r *HTTPRequest) GetHeaderNames(maxHeaderNameLen int) *Values {
 	adapter := func(
 		buf *prim.Char8,
 		bufLen prim.Usize,
@@ -686,7 +686,7 @@ func (r *HTTPRequest) GetHeaderNames() *Values {
 		)
 	}
 
-	return newValues(adapter, MaxHeaderNameLen)
+	return newValues(adapter, maxHeaderNameLen)
 }
 
 // witx:
@@ -713,7 +713,7 @@ func fastlyHTTPReqOriginalHeaderNamesGet(
 
 // GetOriginalHeaderNames returns an iterator that yields the names of each
 // header of the singleton downstream request.
-func GetOriginalHeaderNames() *Values {
+func GetOriginalHeaderNames(maxHeaderNameLen int) *Values {
 	adapter := func(
 		buf *prim.Char8,
 		bufLen prim.Usize,
@@ -730,7 +730,7 @@ func GetOriginalHeaderNames() *Values {
 		)
 	}
 
-	return newValues(adapter, MaxHeaderNameLen)
+	return newValues(adapter, maxHeaderNameLen)
 }
 
 // witx:
@@ -784,8 +784,8 @@ func fastlyHTTPReqHeaderValueGet(
 
 // GetHeaderValue returns the first header value of the given header name on the
 // request, if any.
-func (r *HTTPRequest) GetHeaderValue(name string) (string, error) {
-	buf := prim.NewWriteBuffer(MaxHeaderValueLen)
+func (r *HTTPRequest) GetHeaderValue(name string, maxHeaderValueLen int) (string, error) {
+	buf := prim.NewWriteBuffer(maxHeaderValueLen)
 	if err := fastlyHTTPReqHeaderValueGet(
 		r.h,
 		prim.NewReadBufferFromString(name).ArrayU8(),
@@ -827,7 +827,7 @@ func fastlyHTTPReqHeaderValuesGet(
 
 // GetHeaderValues returns an iterator that yields the values for the named
 // header that are of the request.
-func (r *HTTPRequest) GetHeaderValues(name string) *Values {
+func (r *HTTPRequest) GetHeaderValues(name string, maxHeaderValueLen int) *Values {
 	adapter := func(
 		buf *prim.Char8,
 		bufLen prim.Usize,
@@ -846,7 +846,7 @@ func (r *HTTPRequest) GetHeaderValues(name string) *Values {
 		)
 	}
 
-	return newValues(adapter, MaxHeaderValueLen)
+	return newValues(adapter, maxHeaderValueLen)
 }
 
 // witx:
@@ -983,8 +983,8 @@ func fastlyHTTPReqMethodGet(
 ) FastlyStatus
 
 // GetMethod returns the HTTP method of the request.
-func (r *HTTPRequest) GetMethod() (string, error) {
-	buf := prim.NewWriteBuffer(MaxMethodLen)
+func (r *HTTPRequest) GetMethod(maxMethodLen int) (string, error) {
+	buf := prim.NewWriteBuffer(maxMethodLen)
 	if err := fastlyHTTPReqMethodGet(
 		r.h,
 		buf.Char8Pointer(),
@@ -1042,8 +1042,8 @@ func fastlyHTTPReqURIGet(
 ) FastlyStatus
 
 // GetURI returns the fully qualified URI of the request.
-func (r *HTTPRequest) GetURI() (string, error) {
-	buf := prim.NewWriteBuffer(MaxURLLen)
+func (r *HTTPRequest) GetURI(maxURLLen int) (string, error) {
+	buf := prim.NewWriteBuffer(maxURLLen)
 	if err := fastlyHTTPReqURIGet(
 		r.h,
 		buf.Char8Pointer(),
@@ -1522,7 +1522,7 @@ func fastlyHTTPRespHeaderNamesGet(
 
 // GetHeaderNames returns an iterator that yields the names of each header of
 // the response.
-func (r *HTTPResponse) GetHeaderNames() *Values {
+func (r *HTTPResponse) GetHeaderNames(maxHeaderNameLen int) *Values {
 	adapter := func(
 		buf *prim.Char8,
 		bufLen prim.Usize,
@@ -1540,7 +1540,7 @@ func (r *HTTPResponse) GetHeaderNames() *Values {
 		)
 	}
 
-	return newValues(adapter, MaxHeaderNameLen)
+	return newValues(adapter, maxHeaderNameLen)
 }
 
 // witx:
@@ -1567,8 +1567,8 @@ func fastlyHTTPRespHeaderValueGet(
 
 // GetHeaderValue returns the first header value of the given header name on the
 // response, if any.
-func (r *HTTPResponse) GetHeaderValue(name string) (string, error) {
-	buf := prim.NewWriteBuffer(MaxHeaderValueLen)
+func (r *HTTPResponse) GetHeaderValue(name string, maxHeaderValueLen int) (string, error) {
+	buf := prim.NewWriteBuffer(maxHeaderValueLen)
 	if err := fastlyHTTPRespHeaderValueGet(
 		r.h,
 		prim.NewReadBufferFromString(name).ArrayU8(),
@@ -1610,7 +1610,7 @@ func fastlyHTTPRespHeaderValuesGet(
 
 // GetHeaderValues returns an iterator that yields the values for the named
 // header that are of the response.
-func (r *HTTPResponse) GetHeaderValues(name string) *Values {
+func (r *HTTPResponse) GetHeaderValues(name string, maxHeaderValueLen int) *Values {
 	adapter := func(
 		buf *prim.Char8,
 		bufLen prim.Usize,
@@ -1629,7 +1629,7 @@ func (r *HTTPResponse) GetHeaderValues(name string) *Values {
 		)
 	}
 
-	return newValues(adapter, MaxHeaderValueLen)
+	return newValues(adapter, maxHeaderValueLen)
 }
 
 // witx:
@@ -2268,7 +2268,7 @@ func (s *Secret) Plaintext() ([]byte, error) {
 	// Most secrets will fit into the initial secret buffer size, so
 	// we'll start with that. If it doesn't fit, we'll know the exact
 	// size of the buffer to try again.
-	buf := prim.NewWriteBuffer(InitialSecretLen)
+	buf := prim.NewWriteBuffer(initialSecretLen)
 
 	status := fastlySecretPlaintext(
 		s.h,

internal/abi/fastly/hostcalls_noguest.go

@@ -79,7 +79,7 @@ func NewHTTPRequest() (*HTTPRequest, error) {
 	return nil, fmt.Errorf("not implemented")
 }
 
-func (r *HTTPRequest) GetHeaderNames() *Values {
+func (r *HTTPRequest) GetHeaderNames(maxHeaderNameLen int) *Values {
 	return nil
 }
 
@@ -91,11 +91,11 @@ func GetOriginalHeaderCount() (int, error) {
 	return 0, fmt.Errorf("not implemented")
 }
 
-func (r *HTTPRequest) GetHeaderValue(name string) (string, error) {
+func (r *HTTPRequest) GetHeaderValue(name string, maxHeaderValueLen int) (string, error) {
 	return "", fmt.Errorf("not implemented")
 }
 
-func (r *HTTPRequest) GetHeaderValues(name string) *Values {
+func (r *HTTPRequest) GetHeaderValues(name string, maxHeaderValueLen int) *Values {
 	return nil
 }
 
@@ -115,15 +115,15 @@ func (r *HTTPRequest) RemoveHeader(name string) error {
 	return fmt.Errorf("not implemented")
 }
 
-func (r *HTTPRequest) GetMethod() (string, error) {
+func (r *HTTPRequest) GetMethod(maxMethodLen int) (string, error) {
 	return "", fmt.Errorf("not implemented")
 }
 
 func (r *HTTPRequest) SetMethod(method string) error {
 	return fmt.Errorf("not implemented")
 }
 
-func (r *HTTPRequest) GetURI() (string, error) {
+func (r *HTTPRequest) GetURI(maxURLLen int) (string, error) {
 	return "", fmt.Errorf("not implemented")
 }
 
@@ -179,15 +179,15 @@ func NewHTTPResponse() (*HTTPResponse, error) {
 	return nil, fmt.Errorf("not implemented")
 }
 
-func (r *HTTPResponse) GetHeaderNames() *Values {
+func (r *HTTPResponse) GetHeaderNames(maxHeaderNameLen int) *Values {
 	return nil
 }
 
-func (r *HTTPResponse) GetHeaderValue(name string) (string, error) {
+func (r *HTTPResponse) GetHeaderValue(name string, maxHeaderValueLen int) (string, error) {
 	return "", fmt.Errorf("not implemented")
 }
 
-func (r *HTTPResponse) GetHeaderValues(name string) *Values {
+func (r *HTTPResponse) GetHeaderValues(name string, maxHeaderValueLen int) *Values {
 	return nil
 }