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
diff --git a/include/utils/ResourceTypes.h b/include/utils/ResourceTypes.h
index 49145e8..a845908 100644
--- a/include/utils/ResourceTypes.h
+++ b/include/utils/ResourceTypes.h
@@ -393,7 +393,10 @@
enum {
// If set, the string index is sorted by the string values (based
// on strcmp16()).
- SORTED_FLAG = 1<<0
+ SORTED_FLAG = 1<<0,
+
+ // String pool is encoded in UTF-8
+ UTF8_FLAG = 1<<8
};
uint32_t flags;
@@ -456,9 +459,11 @@
void* mOwnedData;
const ResStringPool_header* mHeader;
size_t mSize;
+ mutable Mutex mDecodeLock;
const uint32_t* mEntries;
const uint32_t* mEntryStyles;
- const char16_t* mStrings;
+ const void* mStrings;
+ char16_t** mCache;
uint32_t mStringPoolSize; // number of uint16_t
const uint32_t* mStyles;
uint32_t mStylePoolSize; // number of uint32_t
diff --git a/include/utils/String16.h b/include/utils/String16.h
index a2d22ee..07a0c11 100644
--- a/include/utils/String16.h
+++ b/include/utils/String16.h
@@ -49,12 +49,17 @@
// Version of strzcmp16 for comparing strings in different endianness.
int strzcmp16_h_n(const char16_t *s1H, size_t n1, const char16_t *s2N, size_t n2);
+// Convert UTF-8 to UTF-16 including surrogate pairs
+void utf8_to_utf16(const uint8_t *src, size_t srcLen, char16_t* dst, const size_t dstLen);
+
}
// ---------------------------------------------------------------------------
namespace android {
+// ---------------------------------------------------------------------------
+
class String8;
class TextOutput;
diff --git a/include/utils/String8.h b/include/utils/String8.h
index ecc5774..c4b18a4 100644
--- a/include/utils/String8.h
+++ b/include/utils/String8.h
@@ -60,6 +60,11 @@
/*
* Returns the UTF-8 length of "src".
*/
+size_t utf8_length_from_utf16(const char16_t *src, size_t src_len);
+
+/*
+ * Returns the UTF-8 length of "src".
+ */
size_t utf8_length_from_utf32(const char32_t *src, size_t src_len);
/*
@@ -120,6 +125,9 @@
size_t utf32_to_utf8(const char32_t* src, size_t src_len,
char* dst, size_t dst_len);
+size_t utf16_to_utf8(const char16_t* src, size_t src_len,
+ char* dst, size_t dst_len);
+
}
// ---------------------------------------------------------------------------
diff --git a/libs/utils/ResourceTypes.cpp b/libs/utils/ResourceTypes.cpp
index 450af8d..afca814 100644
--- a/libs/utils/ResourceTypes.cpp
+++ b/libs/utils/ResourceTypes.cpp
@@ -229,12 +229,12 @@
// --------------------------------------------------------------------
ResStringPool::ResStringPool()
- : mError(NO_INIT), mOwnedData(NULL)
+ : mError(NO_INIT), mOwnedData(NULL), mHeader(NULL), mCache(NULL)
{
}
ResStringPool::ResStringPool(const void* data, size_t size, bool copyData)
- : mError(NO_INIT), mOwnedData(NULL)
+ : mError(NO_INIT), mOwnedData(NULL), mHeader(NULL), mCache(NULL)
{
setTo(data, size, copyData);
}
@@ -296,7 +296,17 @@
(int)size);
return (mError=BAD_TYPE);
}
- mStrings = (const char16_t*)
+
+ size_t charSize;
+ if (mHeader->flags&ResStringPool_header::UTF8_FLAG) {
+ charSize = sizeof(uint8_t);
+ mCache = (char16_t**)malloc(sizeof(char16_t**)*mHeader->stringCount);
+ memset(mCache, 0, sizeof(char16_t**)*mHeader->stringCount);
+ } else {
+ charSize = sizeof(char16_t);
+ }
+
+ mStrings = (const void*)
(((const uint8_t*)data)+mHeader->stringsStart);
if (mHeader->stringsStart >= (mHeader->header.size-sizeof(uint16_t))) {
LOGW("Bad string block: string pool starts at %d, after total size %d\n",
@@ -305,7 +315,7 @@
}
if (mHeader->styleCount == 0) {
mStringPoolSize =
- (mHeader->header.size-mHeader->stringsStart)/sizeof(uint16_t);
+ (mHeader->header.size-mHeader->stringsStart)/charSize;
} else {
// check invariant: styles follow the strings
if (mHeader->stylesStart <= mHeader->stringsStart) {
@@ -314,7 +324,7 @@
return (mError=BAD_TYPE);
}
mStringPoolSize =
- (mHeader->stylesStart-mHeader->stringsStart)/sizeof(uint16_t);
+ (mHeader->stylesStart-mHeader->stringsStart)/charSize;
}
// check invariant: stringCount > 0 requires a string pool to exist
@@ -329,13 +339,19 @@
for (i=0; i<mHeader->stringCount; i++) {
e[i] = dtohl(mEntries[i]);
}
- char16_t* s = const_cast<char16_t*>(mStrings);
- for (i=0; i<mStringPoolSize; i++) {
- s[i] = dtohs(mStrings[i]);
+ if (!(mHeader->flags&ResStringPool_header::UTF8_FLAG)) {
+ const char16_t* strings = (const char16_t*)mStrings;
+ char16_t* s = const_cast<char16_t*>(strings);
+ for (i=0; i<mStringPoolSize; i++) {
+ s[i] = dtohs(strings[i]);
+ }
}
}
- if (mStrings[mStringPoolSize-1] != 0) {
+ if ((mHeader->flags&ResStringPool_header::UTF8_FLAG &&
+ ((uint8_t*)mStrings)[mStringPoolSize-1] != 0) ||
+ (!mHeader->flags&ResStringPool_header::UTF8_FLAG &&
+ ((char16_t*)mStrings)[mStringPoolSize-1] != 0)) {
LOGW("Bad string block: last string is not 0-terminated\n");
return (mError=BAD_TYPE);
}
@@ -410,24 +426,67 @@
free(mOwnedData);
mOwnedData = NULL;
}
+ if (mHeader != NULL && mCache != NULL) {
+ for (size_t x = 0; x < mHeader->stringCount; x++) {
+ if (mCache[x] != NULL) {
+ free(mCache[x]);
+ mCache[x] = NULL;
+ }
+ }
+ free(mCache);
+ mCache = NULL;
+ }
}
+#define DECODE_LENGTH(str, chrsz, len) \
+ len = *(str); \
+ if (*(str)&(1<<(chrsz*8-1))) { \
+ (str)++; \
+ len = (((len)&((1<<(chrsz*8-1))-1))<<(chrsz*8)) + *(str); \
+ } \
+ (str)++;
+
const uint16_t* ResStringPool::stringAt(size_t idx, size_t* outLen) const
{
if (mError == NO_ERROR && idx < mHeader->stringCount) {
- const uint32_t off = (mEntries[idx]/sizeof(uint16_t));
+ const bool isUTF8 = (mHeader->flags&ResStringPool_header::UTF8_FLAG) != 0;
+ const uint32_t off = mEntries[idx]/(isUTF8?sizeof(char):sizeof(char16_t));
if (off < (mStringPoolSize-1)) {
- const char16_t* str = mStrings+off;
- *outLen = *str;
- if ((*str)&0x8000) {
- str++;
- *outLen = (((*outLen)&0x7fff)<<16) + *str;
- }
- if ((uint32_t)(str+1+*outLen-mStrings) < mStringPoolSize) {
- return str+1;
+ if (!isUTF8) {
+ const char16_t* strings = (char16_t*)mStrings;
+ const char16_t* str = strings+off;
+ DECODE_LENGTH(str, sizeof(char16_t), *outLen)
+ if ((uint32_t)(str+*outLen-strings) < mStringPoolSize) {
+ return str;
+ } else {
+ LOGW("Bad string block: string #%d extends to %d, past end at %d\n",
+ (int)idx, (int)(str+*outLen-strings), (int)mStringPoolSize);
+ }
} else {
- LOGW("Bad string block: string #%d extends to %d, past end at %d\n",
- (int)idx, (int)(str+1+*outLen-mStrings), (int)mStringPoolSize);
+ const uint8_t* strings = (uint8_t*)mStrings;
+ const uint8_t* str = strings+off;
+ DECODE_LENGTH(str, sizeof(uint8_t), *outLen)
+ size_t encLen;
+ DECODE_LENGTH(str, sizeof(uint8_t), encLen)
+ if ((uint32_t)(str+encLen-strings) < mStringPoolSize) {
+ AutoMutex lock(mDecodeLock);
+ if (mCache[idx] != NULL) {
+ return mCache[idx];
+ }
+ char16_t *u16str = (char16_t *)calloc(*outLen+1, sizeof(char16_t));
+ if (!u16str) {
+ LOGW("No memory when trying to allocate decode cache for string #%d\n",
+ (int)idx);
+ return NULL;
+ }
+ const unsigned char *u8src = reinterpret_cast<const unsigned char *>(str);
+ utf8_to_utf16(u8src, encLen, u16str, *outLen);
+ mCache[idx] = u16str;
+ return u16str;
+ } else {
+ LOGW("Bad string block: string #%d extends to %d, past end at %d\n",
+ (int)idx, (int)(str+encLen-strings), (int)mStringPoolSize);
+ }
}
} else {
LOGW("Bad string block: string #%d entry is at %d, past end at %d\n",
@@ -466,6 +525,10 @@
size_t len;
+ // TODO optimize searching for UTF-8 strings taking into account
+ // the cache fill to determine when to convert the searched-for
+ // string key to UTF-8.
+
if (mHeader->flags&ResStringPool_header::SORTED_FLAG) {
// Do a binary search for the string...
ssize_t l = 0;
@@ -1043,6 +1106,7 @@
void ResXMLTree::uninit()
{
mError = NO_INIT;
+ mStrings.uninit();
if (mOwnedData) {
free(mOwnedData);
mOwnedData = NULL;
diff --git a/libs/utils/String16.cpp b/libs/utils/String16.cpp
index aef67f2..eab7b2b 100644
--- a/libs/utils/String16.cpp
+++ b/libs/utils/String16.cpp
@@ -172,10 +172,6 @@
: 0);
}
-// ---------------------------------------------------------------------------
-
-namespace android {
-
static inline size_t
utf8_char_len(uint8_t ch)
{
@@ -215,8 +211,38 @@
//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 @@
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");
diff --git a/libs/utils/String8.cpp b/libs/utils/String8.cpp
index e908ec1..3a34838 100644
--- a/libs/utils/String8.cpp
+++ b/libs/utils/String8.cpp
@@ -208,10 +208,23 @@
return getEmptyString();
}
-// Note: not dealing with expanding surrogate pairs.
static char* allocFromUTF16(const char16_t* in, size_t len)
{
- return allocFromUTF16OrUTF32<char16_t, size_t>(in, len);
+ if (len == 0) return getEmptyString();
+
+ const size_t bytes = utf8_length_from_utf16(in, len);
+
+ SharedBuffer* buf = SharedBuffer::alloc(bytes+1);
+ LOG_ASSERT(buf, "Unable to allocate shared buffer");
+ if (buf) {
+ char* str = (char*)buf->data();
+
+ utf16_to_utf8(in, len, str, bytes+1);
+
+ return str;
+ }
+
+ return getEmptyString();
}
static char* allocFromUTF32(const char32_t* in, size_t len)
@@ -762,6 +775,26 @@
return ret;
}
+size_t utf8_length_from_utf16(const char16_t *src, size_t src_len)
+{
+ if (src == NULL || src_len == 0) {
+ return 0;
+ }
+ size_t ret = 0;
+ const char16_t* const end = src + src_len;
+ while (src < end) {
+ if ((*src & 0xFC00) == 0xD800 && (src + 1) < end
+ && (*++src & 0xFC00) == 0xDC00) {
+ // surrogate pairs are always 4 bytes.
+ ret += 4;
+ src++;
+ } else {
+ ret += android::utf32_to_utf8_bytes((char32_t) *src++);
+ }
+ }
+ return ret;
+}
+
static int32_t utf32_at_internal(const char* cur, size_t *num_read)
{
const char first_char = *cur;
@@ -848,3 +881,33 @@
}
return cur - dst;
}
+
+size_t utf16_to_utf8(const char16_t* src, size_t src_len,
+ char* dst, size_t dst_len)
+{
+ if (src == NULL || src_len == 0 || dst == NULL || dst_len == 0) {
+ return 0;
+ }
+ const char16_t* cur_utf16 = src;
+ const char16_t* const end_utf16 = src + src_len;
+ char *cur = dst;
+ const char* const end = dst + dst_len;
+ while (cur_utf16 < end_utf16 && cur < end) {
+ char32_t utf32;
+ // surrogate pairs
+ if ((*cur_utf16 & 0xFC00) == 0xD800 && (cur_utf16 + 1) < end_utf16) {
+ utf32 = (*cur_utf16++ - 0xD800) << 10;
+ utf32 |= *cur_utf16++ - 0xDC00;
+ utf32 += 0x10000;
+ } else {
+ utf32 = (char32_t) *cur_utf16++;
+ }
+ size_t len = android::utf32_to_utf8_bytes(utf32);
+ android::utf32_to_utf8((uint8_t*)cur, utf32, len);
+ cur += len;
+ }
+ if (cur < end) {
+ *cur = '\0';
+ }
+ return cur - dst;
+}