mime: implement TypeByExtension for windows

Fixes #2071.

R=golang-dev, hcwfrichter, pascal, rsc
CC=golang-dev
https://golang.org/cl/5369056

9 files changed, 260 insertions, 49 deletions

diff --git a/src/pkg/mime/Makefile b/src/pkg/mime/Makefile
index 901ed6f8ed..aec5560b9e 100644
--- a/src/pkg/mime/Makefile
+++ b/src/pkg/mime/Makefile
@@ -10,4 +10,24 @@ GOFILES=\
 	mediatype.go\
 	type.go\
 
+GOFILES_freebsd=\
+	type_unix.go
+
+GOFILES_darwin=\
+	type_unix.go
+
+GOFILES_linux=\
+	type_unix.go
+
+GOFILES_openbsd=\
+	type_unix.go
+
+GOFILES_plan9=\
+	type_unix.go
+
+GOFILES_windows=\
+	type_windows.go
+
+GOFILES+=$(GOFILES_$(GOOS))
+
 include ../../Make.pkg
diff --git a/src/pkg/mime/type.go b/src/pkg/mime/type.go
index ce72bb5f7f..e3d968fb81 100644
--- a/src/pkg/mime/type.go
+++ b/src/pkg/mime/type.go
@@ -6,19 +6,11 @@
 package mime
 
 import (
-	"bufio"
 	"fmt"
-	"os"
 	"strings"
 	"sync"
 )
 
-var typeFiles = []string{
-	"/etc/mime.types",
-	"/etc/apache2/mime.types",
-	"/etc/apache/mime.types",
-}
-
 var mimeTypes = map[string]string{
 	".css":  "text/css; charset=utf-8",
 	".gif":  "image/gif",
@@ -33,46 +25,13 @@ var mimeTypes = map[string]string{
 
 var mimeLock sync.RWMutex
 
-func loadMimeFile(filename string) {
-	f, err := os.Open(filename)
-	if err != nil {
-		return
-	}
-
-	reader := bufio.NewReader(f)
-	for {
-		line, err := reader.ReadString('\n')
-		if err != nil {
-			f.Close()
-			return
-		}
-		fields := strings.Fields(line)
-		if len(fields) <= 1 || fields[0][0] == '#' {
-			continue
-		}
-		mimeType := fields[0]
-		for _, ext := range fields[1:] {
-			if ext[0] == '#' {
-				break
-			}
-			setExtensionType("."+ext, mimeType)
-		}
-	}
-}
-
-func initMime() {
-	for _, filename := range typeFiles {
-		loadMimeFile(filename)
-	}
-}
-
 var once sync.Once
 
 // TypeByExtension returns the MIME type associated with the file extension ext.
 // The extension ext should begin with a leading dot, as in ".html".
 // When ext has no associated type, TypeByExtension returns "".
 //
-// The built-in table is small but is is augmented by the local
+// The built-in table is small but on unix it is augmented by the local
 // system's mime.types file(s) if available under one or more of these
 // names:
 //
@@ -80,6 +39,8 @@ var once sync.Once
 //   /etc/apache2/mime.types
 //   /etc/apache/mime.types
 //
+// Windows system mime types are extracted from registry.
+//
 // Text types have the charset parameter set to "utf-8" by default.
 func TypeByExtension(ext string) string {
 	once.Do(initMime)
diff --git a/src/pkg/mime/type_test.go b/src/pkg/mime/type_test.go
index 976f853430..07e1cd5dae 100644
--- a/src/pkg/mime/type_test.go
+++ b/src/pkg/mime/type_test.go
@@ -6,15 +6,9 @@ package mime
 
 import "testing"
 
-var typeTests = map[string]string{
-	".t1":  "application/test",
-	".t2":  "text/test; charset=utf-8",
-	".png": "image/png",
-}
+var typeTests = initMimeForTests()
 
 func TestTypeByExtension(t *testing.T) {
-	typeFiles = []string{"test.types"}
-
 	for ext, want := range typeTests {
 		val := TypeByExtension(ext)
 		if val != want {
diff --git a/src/pkg/mime/type_unix.go b/src/pkg/mime/type_unix.go
new file mode 100644
index 0000000000..45127ba29d
--- /dev/null
+++ b/src/pkg/mime/type_unix.go
@@ -0,0 +1,59 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mime
+
+import (
+	"bufio"
+	"os"
+	"strings"
+)
+
+var typeFiles = []string{
+	"/etc/mime.types",
+	"/etc/apache2/mime.types",
+	"/etc/apache/mime.types",
+}
+
+func loadMimeFile(filename string) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return
+	}
+
+	reader := bufio.NewReader(f)
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			f.Close()
+			return
+		}
+		fields := strings.Fields(line)
+		if len(fields) <= 1 || fields[0][0] == '#' {
+			continue
+		}
+		mimeType := fields[0]
+		for _, ext := range fields[1:] {
+			if ext[0] == '#' {
+				break
+			}
+			setExtensionType("."+ext, mimeType)
+		}
+	}
+}
+
+func initMime() {
+	for _, filename := range typeFiles {
+		loadMimeFile(filename)
+	}
+}
+
+func initMimeForTests() map[string]string {
+	typeFiles = []string{"test.types"}
+	return map[string]string{
+		".t1":  "application/test",
+		".t2":  "text/test; charset=utf-8",
+		".png": "image/png",
+	}
+}
diff --git a/src/pkg/mime/type_windows.go b/src/pkg/mime/type_windows.go
new file mode 100644
index 0000000000..1ac3c4a55d
--- /dev/null
+++ b/src/pkg/mime/type_windows.go
@@ -0,0 +1,62 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mime
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func initMime() {
+	var root syscall.Handle
+	if syscall.RegOpenKeyEx(syscall.HKEY_CLASSES_ROOT, syscall.StringToUTF16Ptr(`\`),
+		0, syscall.KEY_READ, &root) != 0 {
+		return
+	}
+	defer syscall.RegCloseKey(root)
+	var count uint32
+	if syscall.RegQueryInfoKey(root, nil, nil, nil, &count, nil, nil, nil, nil, nil, nil, nil) != 0 {
+		return
+	}
+	var buf [1 << 10]uint16
+	for i := uint32(0); i < count; i++ {
+		n := uint32(len(buf))
+		if syscall.RegEnumKeyEx(root, i, &buf[0], &n, nil, nil, nil, nil) != 0 {
+			continue
+		}
+		ext := syscall.UTF16ToString(buf[:])
+		if len(ext) < 2 || ext[0] != '.' { // looking for extensions only
+			continue
+		}
+		var h syscall.Handle
+		if syscall.RegOpenKeyEx(
+			syscall.HKEY_CLASSES_ROOT, syscall.StringToUTF16Ptr(`\`+ext),
+			0, syscall.KEY_READ, &h) != 0 {
+			continue
+		}
+		var typ uint32
+		n = uint32(len(buf) * 2) // api expects array of bytes, not uint16
+		if syscall.RegQueryValueEx(
+			h, syscall.StringToUTF16Ptr("Content Type"),
+			nil, &typ, (*byte)(unsafe.Pointer(&buf[0])), &n) != 0 {
+			syscall.RegCloseKey(h)
+			continue
+		}
+		syscall.RegCloseKey(h)
+		if typ != syscall.REG_SZ { // null terminated strings only
+			continue
+		}
+		mimeType := syscall.UTF16ToString(buf[:])
+		setExtensionType(ext, mimeType)
+	}
+}
+
+func initMimeForTests() map[string]string {
+	return map[string]string{
+		".bmp": "image/bmp",
+		".png": "image/png",
+		".wav": "audio/wav",
+	}
+}
diff --git a/src/pkg/syscall/syscall_windows.go b/src/pkg/syscall/syscall_windows.go
index de3cb6d49a..5c43f0757b 100644
--- a/src/pkg/syscall/syscall_windows.go
+++ b/src/pkg/syscall/syscall_windows.go
@@ -154,6 +154,11 @@ func NewCallback(fn interface{}) uintptr
 //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
 //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext) = crypt32.CertEnumCertificatesInStore
 //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
+//sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno uintptr) = advapi32.RegOpenKeyExW
+//sys	RegCloseKey(key Handle) (regerrno uintptr) = advapi32.RegCloseKey
+//sys	RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno uintptr) = advapi32.RegQueryInfoKeyW
+//sys	RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno uintptr) = advapi32.RegEnumKeyExW
+//sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno uintptr) = advapi32.RegQueryValueExW
 
 // syscall interface implementation for other packages
 
diff --git a/src/pkg/syscall/zsyscall_windows_386.go b/src/pkg/syscall/zsyscall_windows_386.go
index 7970d3e050..0e202db69c 100644
--- a/src/pkg/syscall/zsyscall_windows_386.go
+++ b/src/pkg/syscall/zsyscall_windows_386.go
@@ -85,6 +85,11 @@ var (
 	procCertOpenSystemStoreW        = modcrypt32.NewProc("CertOpenSystemStoreW")
 	procCertEnumCertificatesInStore = modcrypt32.NewProc("CertEnumCertificatesInStore")
 	procCertCloseStore              = modcrypt32.NewProc("CertCloseStore")
+	procRegOpenKeyExW               = modadvapi32.NewProc("RegOpenKeyExW")
+	procRegCloseKey                 = modadvapi32.NewProc("RegCloseKey")
+	procRegQueryInfoKeyW            = modadvapi32.NewProc("RegQueryInfoKeyW")
+	procRegEnumKeyExW               = modadvapi32.NewProc("RegEnumKeyExW")
+	procRegQueryValueExW            = modadvapi32.NewProc("RegQueryValueExW")
 	procWSAStartup                  = modws2_32.NewProc("WSAStartup")
 	procWSACleanup                  = modws2_32.NewProc("WSACleanup")
 	procWSAIoctl                    = modws2_32.NewProc("WSAIoctl")
@@ -982,6 +987,36 @@ func CertCloseStore(store Handle, flags uint32) (err error) {
 	return
 }
 
+func RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno uintptr) {
+	r0, _, _ := Syscall6(procRegOpenKeyExW.Addr(), 5, uintptr(key), uintptr(unsafe.Pointer(subkey)), uintptr(options), uintptr(desiredAccess), uintptr(unsafe.Pointer(result)), 0)
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegCloseKey(key Handle) (regerrno uintptr) {
+	r0, _, _ := Syscall(procRegCloseKey.Addr(), 1, uintptr(key), 0, 0)
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno uintptr) {
+	r0, _, _ := Syscall12(procRegQueryInfoKeyW.Addr(), 12, uintptr(key), uintptr(unsafe.Pointer(class)), uintptr(unsafe.Pointer(classLen)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(subkeysLen)), uintptr(unsafe.Pointer(maxSubkeyLen)), uintptr(unsafe.Pointer(maxClassLen)), uintptr(unsafe.Pointer(valuesLen)), uintptr(unsafe.Pointer(maxValueNameLen)), uintptr(unsafe.Pointer(maxValueLen)), uintptr(unsafe.Pointer(saLen)), uintptr(unsafe.Pointer(lastWriteTime)))
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno uintptr) {
+	r0, _, _ := Syscall9(procRegEnumKeyExW.Addr(), 8, uintptr(key), uintptr(index), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(nameLen)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(class)), uintptr(unsafe.Pointer(classLen)), uintptr(unsafe.Pointer(lastWriteTime)), 0)
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno uintptr) {
+	r0, _, _ := Syscall6(procRegQueryValueExW.Addr(), 6, uintptr(key), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(valtype)), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(buflen)))
+	regerrno = uintptr(r0)
+	return
+}
+
 func WSAStartup(verreq uint32, data *WSAData) (sockerr uintptr) {
 	r0, _, _ := Syscall(procWSAStartup.Addr(), 2, uintptr(verreq), uintptr(unsafe.Pointer(data)), 0)
 	sockerr = uintptr(r0)
diff --git a/src/pkg/syscall/zsyscall_windows_amd64.go b/src/pkg/syscall/zsyscall_windows_amd64.go
index 49c5fb0fe9..afe8ba41b2 100644
--- a/src/pkg/syscall/zsyscall_windows_amd64.go
+++ b/src/pkg/syscall/zsyscall_windows_amd64.go
@@ -85,6 +85,11 @@ var (
 	procCertOpenSystemStoreW        = modcrypt32.NewProc("CertOpenSystemStoreW")
 	procCertEnumCertificatesInStore = modcrypt32.NewProc("CertEnumCertificatesInStore")
 	procCertCloseStore              = modcrypt32.NewProc("CertCloseStore")
+	procRegOpenKeyExW               = modadvapi32.NewProc("RegOpenKeyExW")
+	procRegCloseKey                 = modadvapi32.NewProc("RegCloseKey")
+	procRegQueryInfoKeyW            = modadvapi32.NewProc("RegQueryInfoKeyW")
+	procRegEnumKeyExW               = modadvapi32.NewProc("RegEnumKeyExW")
+	procRegQueryValueExW            = modadvapi32.NewProc("RegQueryValueExW")
 	procWSAStartup                  = modws2_32.NewProc("WSAStartup")
 	procWSACleanup                  = modws2_32.NewProc("WSACleanup")
 	procWSAIoctl                    = modws2_32.NewProc("WSAIoctl")
@@ -982,6 +987,36 @@ func CertCloseStore(store Handle, flags uint32) (err error) {
 	return
 }
 
+func RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno uintptr) {
+	r0, _, _ := Syscall6(procRegOpenKeyExW.Addr(), 5, uintptr(key), uintptr(unsafe.Pointer(subkey)), uintptr(options), uintptr(desiredAccess), uintptr(unsafe.Pointer(result)), 0)
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegCloseKey(key Handle) (regerrno uintptr) {
+	r0, _, _ := Syscall(procRegCloseKey.Addr(), 1, uintptr(key), 0, 0)
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno uintptr) {
+	r0, _, _ := Syscall12(procRegQueryInfoKeyW.Addr(), 12, uintptr(key), uintptr(unsafe.Pointer(class)), uintptr(unsafe.Pointer(classLen)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(subkeysLen)), uintptr(unsafe.Pointer(maxSubkeyLen)), uintptr(unsafe.Pointer(maxClassLen)), uintptr(unsafe.Pointer(valuesLen)), uintptr(unsafe.Pointer(maxValueNameLen)), uintptr(unsafe.Pointer(maxValueLen)), uintptr(unsafe.Pointer(saLen)), uintptr(unsafe.Pointer(lastWriteTime)))
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno uintptr) {
+	r0, _, _ := Syscall9(procRegEnumKeyExW.Addr(), 8, uintptr(key), uintptr(index), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(nameLen)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(class)), uintptr(unsafe.Pointer(classLen)), uintptr(unsafe.Pointer(lastWriteTime)), 0)
+	regerrno = uintptr(r0)
+	return
+}
+
+func RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno uintptr) {
+	r0, _, _ := Syscall6(procRegQueryValueExW.Addr(), 6, uintptr(key), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(valtype)), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(buflen)))
+	regerrno = uintptr(r0)
+	return
+}
+
 func WSAStartup(verreq uint32, data *WSAData) (sockerr uintptr) {
 	r0, _, _ := Syscall(procWSAStartup.Addr(), 2, uintptr(verreq), uintptr(unsafe.Pointer(data)), 0)
 	sockerr = uintptr(r0)
diff --git a/src/pkg/syscall/ztypes_windows.go b/src/pkg/syscall/ztypes_windows.go
index 1515de81a7..5731a0a831 100644
--- a/src/pkg/syscall/ztypes_windows.go
+++ b/src/pkg/syscall/ztypes_windows.go
@@ -664,3 +664,43 @@ type CertContext struct {
 	CertInfo     uintptr
 	Store        Handle
 }
+
+const (
+	HKEY_CLASSES_ROOT = 0x80000000 + iota
+	HKEY_CURRENT_USER
+	HKEY_LOCAL_MACHINE
+	HKEY_USERS
+	HKEY_PERFORMANCE_DATA
+	HKEY_CURRENT_CONFIG
+	HKEY_DYN_DATA
+
+	KEY_QUERY_VALUE        = 1
+	KEY_SET_VALUE          = 2
+	KEY_CREATE_SUB_KEY     = 4
+	KEY_ENUMERATE_SUB_KEYS = 8
+	KEY_NOTIFY             = 16
+	KEY_CREATE_LINK        = 32
+	KEY_WRITE              = 0x20006
+	KEY_EXECUTE            = 0x20019
+	KEY_READ               = 0x20019
+	KEY_WOW64_64KEY        = 0x0100
+	KEY_WOW64_32KEY        = 0x0200
+	KEY_ALL_ACCESS         = 0xf003f
+)
+
+const (
+	REG_NONE = iota
+	REG_SZ
+	REG_EXPAND_SZ
+	REG_BINARY
+	REG_DWORD_LITTLE_ENDIAN
+	REG_DWORD_BIG_ENDIAN
+	REG_LINK
+	REG_MULTI_SZ
+	REG_RESOURCE_LIST
+	REG_FULL_RESOURCE_DESCRIPTOR
+	REG_RESOURCE_REQUIREMENTS_LIST
+	REG_QWORD_LITTLE_ENDIAN
+	REG_DWORD = REG_DWORD_LITTLE_ENDIAN
+	REG_QWORD = REG_QWORD_LITTLE_ENDIAN
+)