From a859ae02ad26c8a319ae1ab2900e846a97154ce9 Mon Sep 17 00:00:00 2001
From: Leonid Bugaev <leonsbox@gmail.com>
Date: Mon, 6 Jul 2015 18:36:12 +0500
Subject: [PATCH] More tests and simplify hashFilter

---
 http_modifier.go                |  3 +-
 http_modifier_test.go           | 57 +++++++++++++++++++++++++++++++++
 settings_header_hash_filters.go | 12 ++-----
 settings_url_map_test.go        | 19 ++++++++++-
 4 files changed, 79 insertions(+), 12 deletions(-)

diff --git a/http_modifier.go b/http_modifier.go
index 95fb819..2f1dc3d 100644
--- a/http_modifier.go
+++ b/http_modifier.go
@@ -68,7 +68,8 @@ func (m *HTTPModifier) Rewrite(payload []byte) (response []byte) {
 
             hasher := fnv.New32a()
             hasher.Write(value)
-            if hasher.Sum32() > f.maxHash {
+
+            if (hasher.Sum32() % 100) >= f.percent {
                 return
             }
         }
diff --git a/http_modifier_test.go b/http_modifier_test.go
index 6ca055d..6803587 100644
--- a/http_modifier_test.go
+++ b/http_modifier_test.go
@@ -2,6 +2,8 @@ package main
 
 import (
     "testing"
+    "github.com/buger/gor/proto"
+    "bytes"
 )
 
 func TestHTTPModifierWithoutConfig(t *testing.T) {
@@ -36,3 +38,58 @@ func TestHTTPModifierHeaderFilters(t *testing.T) {
         t.Error("Request should not pass filters")
     }
 }
+
+
+func TestHTTPModifierURLRegexp(t *testing.T) {
+    var url, new_url []byte
+
+    rewrites := UrlRewriteMap{}
+
+    payload := func(url []byte) []byte {
+        return []byte("POST " + string(url) + " HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+    }
+
+    err := rewrites.Set("/v1/user/([^\\/]+)/ping:/v2/user/$1/ping")
+    if err != nil {
+        t.Error("Should not error on /v1/user/([^\\/]+)/ping:/v2/user/$1/ping")
+    }
+
+    modifier := NewHTTPModifier(&HTTPModifierConfig{
+        urlRewrite: rewrites,
+    })
+
+    url = []byte("/v1/user/joe/ping")
+    if new_url = proto.Path(modifier.Rewrite(payload(url))); bytes.Equal(new_url, url) {
+        t.Error("Request url should have been rewritten, wasn't", string(new_url))
+    }
+
+    url = []byte("/v1/user/ping")
+    if new_url = proto.Path(modifier.Rewrite(payload(url))); !bytes.Equal(new_url, url) {
+        t.Error("Request url should have been rewritten, wasn't", string(new_url))
+    }
+}
+
+func TestHTTPModifierHeaderHashFilters(t *testing.T) {
+    filters := HTTPHeaderHashFilters{}
+    filters.Set("Header2:1/2")
+
+    modifier := NewHTTPModifier(&HTTPModifierConfig{
+        headerHashFilters: filters,
+    })
+
+    payload := func(header []byte) []byte {
+        return []byte("POST / HTTP/1.1\r\n" + string(header) + "Content-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+    }
+
+    if p := modifier.Rewrite(payload([]byte(""))); len(p) > 0 {
+        t.Error("Request should not pass filters, Header2 does not exist")
+    }
+
+    if p := modifier.Rewrite(payload([]byte("Header2: 3\r\n"))); len(p) > 0 {
+        t.Error("Request should not pass filters, Header2 hash too high")
+    }
+
+    if p := modifier.Rewrite(payload([]byte("Header2: 1\r\n"))); len(p) == 0 {
+        t.Error("Request should pass filters")
+    }
+}
diff --git a/settings_header_hash_filters.go b/settings_header_hash_filters.go
index 0dc9801..5c848fe 100644
--- a/settings_header_hash_filters.go
+++ b/settings_header_hash_filters.go
@@ -9,7 +9,7 @@ import (
 
 type headerHashFilter struct {
 	name    []byte
-	maxHash uint32
+	percent uint32
 }
 
 type HTTPHeaderHashFilters []headerHashFilter
@@ -33,17 +33,9 @@ func (h *HTTPHeaderHashFilters) Set(value string) error {
 	num, _ = strconv.ParseUint(fracArr[0], 10, 64)
 	den, _ = strconv.ParseUint(fracArr[1], 10, 64)
 
-	if num < 1 || den < 1 || num > den {
-		panic("need positive numerators and denominators, with the former less than the latter.")
-	}
-
-	if den&(den-1) != 0 {
-		return errors.New("must have a denominator which is a power of two.")
-	}
-
 	var f headerHashFilter
 	f.name = []byte(valArr[0])
-	f.maxHash = (uint32)(num * (((uint64)(2 << 31)) / den))
+	f.percent = uint32((float64(num) / float64(den)) * 100)
 	*h = append(*h, f)
 
 	return nil
diff --git a/settings_url_map_test.go b/settings_url_map_test.go
index 85f0393..de7ad7d 100644
--- a/settings_url_map_test.go
+++ b/settings_url_map_test.go
@@ -1 +1,18 @@
-package main
\ No newline at end of file
+package main
+
+import (
+    "testing"
+)
+
+func TestUrlRewriteMap(t *testing.T) {
+    var err error
+    rewrites := UrlRewriteMap{}
+
+    if err = rewrites.Set("/v1/user/([^\\/]+)/ping:/v2/user/$1/ping"); err != nil {
+        t.Error("Should set mapping", err)
+    }
+
+    if err = rewrites.Set("/v1/user/([^\\/]+)/ping"); err == nil {
+        t.Error("Should not set mapping without :")
+    }
+}
\ No newline at end of file