Optional use of UTF-8 strings in resource bundles

Allows the use of UTF-8 for packing resources instead of the
default of UTF-16 for Java. When strings are extracted from the
ResStringPool, they are converted to UTF-16 and the result is
cached for subsequent calls.

When using aapt to package, add in the "-8" switch to pack the
resources using UTF-8. This will result in the value, key, and
type strings as well as the compiled XML string values taking
significantly less space in the final application package in
most scenarios.

Change-Id: I129483f8b3d3b1c5869dced05cb525e494a6c83a

1 files changed, 34 insertions, 24 deletions

diff --git a/libs/utils/String16.cpp b/libs/utils/String16.cpp
index aef67f22af..eab7b2b926 100644
--- a/libs/utils/String16.cpp
+++ b/libs/utils/String16.cpp
@@ -172,10 +172,6 @@ int strzcmp16_h_n(const char16_t *s1H, size_t n1, const char16_t *s2N, size_t n2
            : 0);
 }
 
-// ---------------------------------------------------------------------------
-
-namespace android {
-
 static inline size_t
 utf8_char_len(uint8_t ch)
 {
@@ -215,8 +211,38 @@ utf8_to_utf32(const uint8_t *src, size_t length)
     //printf("Char at %p: len=%d, utf-16=%p\n", src, length, (void*)result);
 }
 
+void
+utf8_to_utf16(const uint8_t *src, size_t srcLen,
+        char16_t* dst, const size_t dstLen)
+{
+    const uint8_t* const end = src + srcLen;
+    const char16_t* const dstEnd = dst + dstLen;
+    while (src < end && dst < dstEnd) {
+        size_t len = utf8_char_len(*src);
+        uint32_t codepoint = utf8_to_utf32((const uint8_t*)src, len);
+
+        // Convert the UTF32 codepoint to one or more UTF16 codepoints
+        if (codepoint <= 0xFFFF) {
+            // Single UTF16 character
+            *dst++ = (char16_t) codepoint;
+        } else {
+            // Multiple UTF16 characters with surrogates
+            codepoint = codepoint - 0x10000;
+            *dst++ = (char16_t) ((codepoint >> 10) + 0xD800);
+            *dst++ = (char16_t) ((codepoint & 0x3FF) + 0xDC00);
+        }
+
+        src += len;
+    }
+    if (dst < dstEnd) {
+        *dst = 0;
+    }
+}
+
 // ---------------------------------------------------------------------------
 
+namespace android {
+
 static SharedBuffer* gEmptyStringBuf = NULL;
 static char16_t* gEmptyString = NULL;
 
@@ -260,30 +286,14 @@ static char16_t* allocFromUTF8(const char* in, size_t len)
         p += utf8len;
     }
     
-    SharedBuffer* buf = SharedBuffer::alloc((chars+1)*sizeof(char16_t));
+    size_t bufSize = (chars+1)*sizeof(char16_t);
+    SharedBuffer* buf = SharedBuffer::alloc(bufSize);
     if (buf) {
         p = in;
         char16_t* str = (char16_t*)buf->data();
-        char16_t* d = str;
-        while (p < end) {
-            size_t len = utf8_char_len(*p);
-            uint32_t codepoint = utf8_to_utf32((const uint8_t*)p, len);
-
-            // Convert the UTF32 codepoint to one or more UTF16 codepoints
-            if (codepoint <= 0xFFFF) {
-                // Single UTF16 character
-                *d++ = (char16_t) codepoint;
-            } else {
-                // Multiple UTF16 characters with surrogates
-                codepoint = codepoint - 0x10000;
-                *d++ = (char16_t) ((codepoint >> 10) + 0xD800);
-                *d++ = (char16_t) ((codepoint & 0x3FF) + 0xDC00);
-            }
-
-            p += len;
-        }
-        *d = 0;
         
+        utf8_to_utf16((const uint8_t*)p, len, str, bufSize);
+
         //printf("Created UTF-16 string from UTF-8 \"%s\":", in);
         //printHexData(1, str, buf->size(), 16, 1);
         //printf("\n");