Improve support for external keyboards.

Use Vendor ID, Product ID and optionally the Version to
locate keymaps and configuration files for external devices.

Moved virtual key definition parsing to native code so that
EventHub can identify touch screens with virtual keys and load
the appropriate key layout file.

Cleaned up a lot of old code in EventHub.

Fixed a regression in ViewRoot's fallback event handling.

Fixed a minor bug in FileMap that caused it to try to munmap
or close invalid handled when released if the attempt to map
the file failed.

Added a couple of new String8 conveniences for formatting strings.

Modified Tokenizer to fall back to open+read when mmap fails since
we can't mmap sysfs files as needed to open the virtual key
definition files in /sys/board_properties/.

Change-Id: I6ca5e5f9547619fd082ddac47e87ce185da69ee6
diff --git a/include/utils/String8.h b/include/utils/String8.h
index 6abfb06..6b49ff5 100644
--- a/include/utils/String8.h
+++ b/include/utils/String8.h
@@ -47,7 +47,12 @@
     explicit                    String8(const char32_t* o);
     explicit                    String8(const char32_t* o, size_t numChars);
                                 ~String8();
-    
+
+    static inline const String8 empty();
+
+    static String8              format(const char* fmt, ...) __attribute__((format (printf, 1, 2)));
+    static String8              formatV(const char* fmt, va_list args);
+
     inline  const char*         string() const;
     inline  size_t              size() const;
     inline  size_t              length() const;
@@ -229,6 +234,10 @@
     return compare_type(lhs, rhs) < 0;
 }
 
+inline const String8 String8::empty() {
+    return String8();
+}
+
 inline const char* String8::string() const
 {
     return mString;
diff --git a/include/utils/Tokenizer.h b/include/utils/Tokenizer.h
index 21e58e6..c7db5fb 100644
--- a/include/utils/Tokenizer.h
+++ b/include/utils/Tokenizer.h
@@ -28,7 +28,7 @@
  * A simple tokenizer for loading and parsing ASCII text files line by line.
  */
 class Tokenizer {
-    Tokenizer(const String8& filename, FileMap* fileMap, const char* buffer, size_t length);
+    Tokenizer(const String8& filename, FileMap* fileMap, char* buffer, size_t length);
 
 public:
     ~Tokenizer();
@@ -110,7 +110,7 @@
 
     String8 mFilename;
     FileMap* mFileMap;
-    const char* mBuffer;
+    char* mBuffer;
     size_t mLength;
 
     const char* mCurrent;
diff --git a/libs/utils/FileMap.cpp b/libs/utils/FileMap.cpp
index e1ba9b2..f1f8bda 100644
--- a/libs/utils/FileMap.cpp
+++ b/libs/utils/FileMap.cpp
@@ -63,16 +63,18 @@
         free(mFileName);
     }
 #ifdef HAVE_POSIX_FILEMAP    
-    if (munmap(mBasePtr, mBaseLength) != 0) {
+    if (mBasePtr && munmap(mBasePtr, mBaseLength) != 0) {
         LOGD("munmap(%p, %d) failed\n", mBasePtr, (int) mBaseLength);
     }
 #endif
 #ifdef HAVE_WIN32_FILEMAP
-    if ( UnmapViewOfFile(mBasePtr) == 0) {
+    if (mBasePtr && UnmapViewOfFile(mBasePtr) == 0) {
         LOGD("UnmapViewOfFile(%p) failed, error = %ld\n", mBasePtr, 
               GetLastError() );
     }
-    CloseHandle(mFileMapping);
+    if (mFileMapping != INVALID_HANDLE_VALUE) {
+        CloseHandle(mFileMapping);
+    }
     CloseHandle(mFileHandle);
 #endif
 }
diff --git a/libs/utils/String8.cpp b/libs/utils/String8.cpp
index e531a2a..0bc5aff 100644
--- a/libs/utils/String8.cpp
+++ b/libs/utils/String8.cpp
@@ -195,6 +195,24 @@
     SharedBuffer::bufferFromData(mString)->release();
 }
 
+String8 String8::format(const char* fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+
+    String8 result(formatV(fmt, args));
+
+    va_end(args);
+    return result;
+}
+
+String8 String8::formatV(const char* fmt, va_list args)
+{
+    String8 result;
+    result.appendFormatV(fmt, args);
+    return result;
+}
+
 void String8::clear() {
     SharedBuffer::bufferFromData(mString)->release();
     mString = getEmptyString();
diff --git a/libs/utils/Tokenizer.cpp b/libs/utils/Tokenizer.cpp
index 9251973..b3445b7 100644
--- a/libs/utils/Tokenizer.cpp
+++ b/libs/utils/Tokenizer.cpp
@@ -35,16 +35,16 @@
     return strchr(delimiters, ch) != NULL;
 }
 
-
-Tokenizer::Tokenizer(const String8& filename, FileMap* fileMap,
-        const char* buffer, size_t length) :
-        mFilename(filename), mFileMap(fileMap), mBuffer(buffer), mLength(length),
-        mCurrent(buffer), mLineNumber(1) {
+Tokenizer::Tokenizer(const String8& filename, FileMap* fileMap, char* buffer, size_t length) :
+        mFilename(filename), mFileMap(fileMap),
+        mBuffer(buffer), mLength(length), mCurrent(buffer), mLineNumber(1) {
 }
 
 Tokenizer::~Tokenizer() {
     if (mFileMap) {
         mFileMap->release();
+    } else {
+        delete[] mBuffer;
     }
 }
 
@@ -63,22 +63,33 @@
             LOGE("Error getting size of file '%s', %s.", filename.string(), strerror(errno));
         } else {
             size_t length = size_t(stat.st_size);
-            FileMap* fileMap = new FileMap();
-            if (!fileMap->create(NULL, fd, 0, length, true)) {
-                result = NO_MEMORY;
-                LOGE("Error mapping file '%s', %s.", filename.string(), strerror(errno));
-            } else {
-                fileMap->advise(FileMap::SEQUENTIAL);
 
-                *outTokenizer = new Tokenizer(filename, fileMap,
-                        static_cast<const char*>(fileMap->getDataPtr()), length);
-                if (!*outTokenizer) {
-                    result = NO_MEMORY;
-                    LOGE("Error allocating tokenizer for file=%s.", filename.string());
+            FileMap* fileMap = new FileMap();
+            char* buffer;
+            if (fileMap->create(NULL, fd, 0, length, true)) {
+                fileMap->advise(FileMap::SEQUENTIAL);
+                buffer = static_cast<char*>(fileMap->getDataPtr());
+            } else {
+                fileMap->release();
+                fileMap = NULL;
+
+                // Fall back to reading into a buffer since we can't mmap files in sysfs.
+                // The length we obtained from stat is wrong too (it will always be 4096)
+                // so we must trust that read will read the entire file.
+                buffer = new char[length];
+                ssize_t nrd = read(fd, buffer, length);
+                if (nrd < 0) {
+                    result = -errno;
+                    LOGE("Error reading file '%s', %s.", filename.string(), strerror(errno));
+                    delete[] buffer;
+                    buffer = NULL;
+                } else {
+                    length = size_t(nrd);
                 }
             }
-            if (result) {
-                fileMap->release();
+
+            if (!result) {
+                *outTokenizer = new Tokenizer(filename, fileMap, buffer, length);
             }
         }
         close(fd);