Add http_response package

3 months ago · 8f35139a5e
parent 04f79a71d8
commit 8f35139a5e
2 changed files with 203 additions and 0 deletions
--- a/http_response/http_response.go
+++ b/http_response/http_response.go
@ -0,0 +1,139 @@
+package http_response
+
+import (
+	"bytes"
+	"regexp"
+)
+
+type HttpResponseHeader interface {
+	Name() []byte
+	Value() []byte
+	NormalizedValue() []byte
+}
+
+type HttpResponse interface {
+	Status() []byte
+	Headers() []HttpResponseHeader
+	Body() []byte
+}
+
+type httpResponseHeader struct {
+	name            []byte
+	value           []byte
+	normalizedValue []byte
+}
+
+func (h httpResponseHeader) Name() []byte {
+	return h.name
+}
+
+func (h httpResponseHeader) Value() []byte {
+	return h.value
+}
+
+func (h httpResponseHeader) NormalizedValue() []byte {
+	if h.normalizedValue == nil {
+		h.normalizedValue = normalizeHeaderValue(h.value)
+	}
+	return h.normalizedValue
+}
+
+var normalizeValueRe *regexp.Regexp
+
+func normalizeHeaderValue(value []byte) []byte {
+	if normalizeValueRe == nil {
+		str := `\s*\n\s+`
+		normalizeValueRe = regexp.MustCompile(str)
+	}
+
+	return normalizeValueRe.ReplaceAllLiteral(bytes.TrimSpace(value), []byte{' '})
+}
+
+type FailedParsingHttpResponseError struct {
+	error string
+}
+
+func (e FailedParsingHttpResponseError) Error() string {
+	return e.error
+}
+
+var splitHttpResponseRe *regexp.Regexp
+
+func splitHttpResponse(text []byte) (status []byte, headers []byte, body []byte, ok bool) {
+	if splitHttpResponseRe == nil {
+		str := `(?ms)\A(?P<status>(?:HTTP/\d\.\d \d{3} \w+|HTTP/2 [^\n]+))\n(?P<headers>.*?\n)\n(?P<body>.*)\z`
+		splitHttpResponseRe = regexp.MustCompile(str)
+	}
+
+	match := splitHttpResponseRe.FindSubmatch(text)
+	if match == nil {
+		return
+	}
+
+	status = match[1]
+	headers = match[2]
+	body = match[3]
+	ok = true
+
+	return
+}
+
+var splitHeadersRe *regexp.Regexp
+
+func splitHeaders(text []byte) (headers []HttpResponseHeader, ok bool) {
+	if splitHeadersRe == nil {
+		str := `(?m)\A(?:^(?P<field>[^:\s]+):\s+(?P<value>.*$\n(?:^\s+.*$\n)*))`
+		splitHeadersRe = regexp.MustCompile(str)
+	}
+
+	for p := 0; p < len(text); {
+		match := splitHeadersRe.FindSubmatch(text[p:])
+		if match == nil {
+			return nil, false
+		}
+		name := match[1]
+		value := bytes.TrimRight(match[2], "\n")
+		headers = append(headers, httpResponseHeader{name, value, nil})
+		p += len(match[0])
+	}
+
+	ok = true
+
+	return
+}
+
+func normalizeEols(text []byte) []byte {
+	return bytes.ReplaceAll(text, []byte{'\r', '\n'}, []byte{'\n'})
+}
+
+type httpResponse struct {
+	status  []byte
+	headers []HttpResponseHeader
+	body    []byte
+}
+
+func NewHttpResponseFromText(text []byte) (HttpResponse, error) {
+	status, combinedHeaders, body, ok := splitHttpResponse(normalizeEols(text))
+	if !ok {
+		return nil, FailedParsingHttpResponseError{"failed extracting status, headers or body"}
+	}
+
+	headers, ok := splitHeaders(combinedHeaders)
+	if !ok {
+		return nil, FailedParsingHttpResponseError{"failed parsing headers"}
+	}
+
+	return httpResponse{status, headers, body}, nil
+}
+
+func (r httpResponse) Status() []byte {
+	return r.status
+}
+
+func (r httpResponse) Headers() []HttpResponseHeader {
+	return r.headers
+}
+
+func (r httpResponse) Body() []byte {
+	return r.body
+}
--- a/http_response/http_response_test.go
+++ b/http_response/http_response_test.go
@ -0,0 +1,64 @@
+package http_response
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_normalizeHeaderValue(t *testing.T) {
+	require.Equal(t, "a  b", string(normalizeHeaderValue([]byte("a  b"))))
+	require.Equal(t, "a  b", string(normalizeHeaderValue([]byte("a  b "))))
+	require.Equal(t, "a  b", string(normalizeHeaderValue([]byte(" a  b"))))
+	require.Equal(t, "a b", string(normalizeHeaderValue([]byte(" a \n b "))))
+}
+
+func Test_splitHttpResponse(t *testing.T) {
+	_, _, _, ok := splitHttpResponse([]byte("whatever"))
+	require.False(t, ok)
+
+	_, _, _, ok = splitHttpResponse([]byte("HTTP/1.1 200 OK\n\nbody"))
+	require.False(t, ok)
+
+	status, header, body, ok := splitHttpResponse([]byte("HTTP/1.1 200 OK\nheader1: value\nheader2: value\n with\n continuation\n\nbody"))
+	require.True(t, ok)
+	require.Equal(t, "HTTP/1.1 200 OK", string(status))
+	require.Equal(t, "header1: value\nheader2: value\n with\n continuation\n", string(header))
+	require.Equal(t, "body", string(body))
+
+	status, header, body, ok = splitHttpResponse([]byte("HTTP/2 200 \ndate: Sun, 17 Mar 2024 21:58:03 GMT\n\n{}"))
+	require.True(t, ok)
+	require.Equal(t, "HTTP/2 200 ", string(status))
+	require.Equal(t, "date: Sun, 17 Mar 2024 21:58:03 GMT\n", string(header))
+	require.Equal(t, "{}", string(body))
+}
+
+func Test_splitHeaders(t *testing.T) {
+	_, ok := splitHeaders([]byte("whatever"))
+	require.False(t, ok)
+
+	_, ok = splitHeaders([]byte("a: b\nwhatever\n"))
+	require.False(t, ok)
+
+	res, ok := splitHeaders([]byte("a: b\n"))
+	require.True(t, ok)
+	require.Len(t, res, 1)
+	require.Equal(t, "a", string(res[0].Name()))
+	require.Equal(t, "b", string(res[0].Value()))
+	require.Equal(t, "b", string(res[0].NormalizedValue()))
+
+	res, ok = splitHeaders([]byte("a: b1\n  b2\n  b3\n"))
+	require.True(t, ok)
+	require.Len(t, res, 1)
+	require.Equal(t, "a", string(res[0].Name()))
+	require.Equal(t, "b1\n  b2\n  b3", string(res[0].Value()))
+	require.Equal(t, "b1 b2 b3", string(res[0].NormalizedValue()))
+
+	res, ok = splitHeaders([]byte("a: b\nc: d\n"))
+	require.True(t, ok)
+	require.Len(t, res, 2)
+	require.Equal(t, "a", string(res[0].Name()))
+	require.Equal(t, "b", string(res[0].Value()))
+	require.Equal(t, "c", string(res[1].Name()))
+	require.Equal(t, "d", string(res[1].Value()))
+}