frameworks/native: move Zip* from libandroidfw to libutils

ZipUtils is needed by build/tools, move it from libandroidfw
(frameworks/base) to libutils (frameworks/native).

Change-Id: Ib8c41134ccdec6d6aa8d49860f8dddef49a24783

9 files changed, 1790 insertions, 2 deletions

diff --git a/include/utils/ZipFileCRO.h b/include/utils/ZipFileCRO.h
new file mode 100644
index 0000000..3e42a95
--- /dev/null
+++ b/include/utils/ZipFileCRO.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// C API for ead-only access to Zip archives, with minimal heap allocation.
+//
+#ifndef __LIBS_ZIPFILECRO_H
+#define __LIBS_ZIPFILECRO_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <utils/Compat.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Trivial typedef to ensure that ZipFileCRO is not treated as a simple integer.
+ */
+typedef void* ZipFileCRO;
+
+/*
+ * Trivial typedef to ensure that ZipEntryCRO is not treated as a simple
+ * integer.  We use NULL to indicate an invalid value.
+ */
+typedef void* ZipEntryCRO;
+
+extern ZipFileCRO ZipFileXRO_open(const char* path);
+
+extern void ZipFileCRO_destroy(ZipFileCRO zip);
+
+extern ZipEntryCRO ZipFileCRO_findEntryByName(ZipFileCRO zip,
+        const char* fileName);
+
+extern bool ZipFileCRO_getEntryInfo(ZipFileCRO zip, ZipEntryCRO entry,
+        int* pMethod, size_t* pUncompLen,
+        size_t* pCompLen, off64_t* pOffset, long* pModWhen, long* pCrc32);
+
+extern bool ZipFileCRO_uncompressEntry(ZipFileCRO zip, ZipEntryCRO entry, int fd);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*__LIBS_ZIPFILECRO_H*/
diff --git a/include/utils/ZipFileRO.h b/include/utils/ZipFileRO.h
new file mode 100644
index 0000000..547e36a
--- /dev/null
+++ b/include/utils/ZipFileRO.h
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Read-only access to Zip archives, with minimal heap allocation.
+ *
+ * This is similar to the more-complete ZipFile class, but no attempt
+ * has been made to make them interchangeable.  This class operates under
+ * a very different set of assumptions and constraints.
+ *
+ * One such assumption is that if you're getting file descriptors for
+ * use with this class as a child of a fork() operation, you must be on
+ * a pread() to guarantee correct operation. This is because pread() can
+ * atomically read at a file offset without worrying about a lock around an
+ * lseek() + read() pair.
+ */
+#ifndef __LIBS_ZIPFILERO_H
+#define __LIBS_ZIPFILERO_H
+
+#include <utils/Compat.h>
+#include <utils/Errors.h>
+#include <utils/FileMap.h>
+#include <utils/threads.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+
+namespace android {
+
+/*
+ * Trivial typedef to ensure that ZipEntryRO is not treated as a simple
+ * integer.  We use NULL to indicate an invalid value.
+ */
+typedef void* ZipEntryRO;
+
+/*
+ * Open a Zip archive for reading.
+ *
+ * We want "open" and "find entry by name" to be fast operations, and we
+ * want to use as little memory as possible.  We memory-map the file,
+ * and load a hash table with pointers to the filenames (which aren't
+ * null-terminated).  The other fields are at a fixed offset from the
+ * filename, so we don't need to extract those (but we do need to byte-read
+ * and endian-swap them every time we want them).
+ *
+ * To speed comparisons when doing a lookup by name, we could make the mapping
+ * "private" (copy-on-write) and null-terminate the filenames after verifying
+ * the record structure.  However, this requires a private mapping of
+ * every page that the Central Directory touches.  Easier to tuck a copy
+ * of the string length into the hash table entry.
+ *
+ * NOTE: If this is used on file descriptors inherited from a fork() operation,
+ * you must be on a platform that implements pread() to guarantee correctness
+ * on the shared file descriptors.
+ */
+class ZipFileRO {
+public:
+    ZipFileRO()
+        : mFd(-1), mFileName(NULL), mFileLength(-1),
+          mDirectoryMap(NULL),
+          mNumEntries(-1), mDirectoryOffset(-1),
+          mHashTableSize(-1), mHashTable(NULL)
+        {}
+
+    ~ZipFileRO();
+
+    /*
+     * Open an archive.
+     */
+    status_t open(const char* zipFileName);
+
+    /*
+     * Find an entry, by name.  Returns the entry identifier, or NULL if
+     * not found.
+     *
+     * If two entries have the same name, one will be chosen at semi-random.
+     */
+    ZipEntryRO findEntryByName(const char* fileName) const;
+
+    /*
+     * Return the #of entries in the Zip archive.
+     */
+    int getNumEntries(void) const {
+        return mNumEntries;
+    }
+
+    /*
+     * Return the Nth entry.  Zip file entries are not stored in sorted
+     * order, and updated entries may appear at the end, so anyone walking
+     * the archive needs to avoid making ordering assumptions.  We take
+     * that further by returning the Nth non-empty entry in the hash table
+     * rather than the Nth entry in the archive.
+     *
+     * Valid values are [0..numEntries).
+     *
+     * [This is currently O(n).  If it needs to be fast we can allocate an
+     * additional data structure or provide an iterator interface.]
+     */
+    ZipEntryRO findEntryByIndex(int idx) const;
+
+    /*
+     * Copy the filename into the supplied buffer.  Returns 0 on success,
+     * -1 if "entry" is invalid, or the filename length if it didn't fit.  The
+     * length, and the returned string, include the null-termination.
+     */
+    int getEntryFileName(ZipEntryRO entry, char* buffer, int bufLen) const;
+
+    /*
+     * Get the vital stats for an entry.  Pass in NULL pointers for anything
+     * you don't need.
+     *
+     * "*pOffset" holds the Zip file offset of the entry's data.
+     *
+     * Returns "false" if "entry" is bogus or if the data in the Zip file
+     * appears to be bad.
+     */
+    bool getEntryInfo(ZipEntryRO entry, int* pMethod, size_t* pUncompLen,
+        size_t* pCompLen, off64_t* pOffset, long* pModWhen, long* pCrc32) const;
+
+    /*
+     * Create a new FileMap object that maps a subset of the archive.  For
+     * an uncompressed entry this effectively provides a pointer to the
+     * actual data, for a compressed entry this provides the input buffer
+     * for inflate().
+     */
+    FileMap* createEntryFileMap(ZipEntryRO entry) const;
+
+    /*
+     * Uncompress the data into a buffer.  Depending on the compression
+     * format, this is either an "inflate" operation or a memcpy.
+     *
+     * Use "uncompLen" from getEntryInfo() to determine the required
+     * buffer size.
+     *
+     * Returns "true" on success.
+     */
+    bool uncompressEntry(ZipEntryRO entry, void* buffer) const;
+
+    /*
+     * Uncompress the data to an open file descriptor.
+     */
+    bool uncompressEntry(ZipEntryRO entry, int fd) const;
+
+    /* Zip compression methods we support */
+    enum {
+        kCompressStored     = 0,        // no compression
+        kCompressDeflated   = 8,        // standard deflate
+    };
+
+    /*
+     * Utility function: uncompress deflated data, buffer to buffer.
+     */
+    static bool inflateBuffer(void* outBuf, const void* inBuf,
+        size_t uncompLen, size_t compLen);
+
+    /*
+     * Utility function: uncompress deflated data, buffer to fd.
+     */
+    static bool inflateBuffer(int fd, const void* inBuf,
+        size_t uncompLen, size_t compLen);
+
+    /*
+     * Utility function to convert ZIP's time format to a timespec struct.
+     */
+    static inline void zipTimeToTimespec(long when, struct tm* timespec) {
+        const long date = when >> 16;
+        timespec->tm_year = ((date >> 9) & 0x7F) + 80; // Zip is years since 1980
+        timespec->tm_mon = (date >> 5) & 0x0F;
+        timespec->tm_mday = date & 0x1F;
+
+        timespec->tm_hour = (when >> 11) & 0x1F;
+        timespec->tm_min = (when >> 5) & 0x3F;
+        timespec->tm_sec = (when & 0x1F) << 1;
+    }
+
+    /*
+     * Some basic functions for raw data manipulation.  "LE" means
+     * Little Endian.
+     */
+    static inline unsigned short get2LE(const unsigned char* buf) {
+        return buf[0] | (buf[1] << 8);
+    }
+    static inline unsigned long get4LE(const unsigned char* buf) {
+        return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
+    }
+
+private:
+    /* these are private and not defined */ 
+    ZipFileRO(const ZipFileRO& src);
+    ZipFileRO& operator=(const ZipFileRO& src);
+
+    /* locate and parse the central directory */
+    bool mapCentralDirectory(void);
+
+    /* parse the archive, prepping internal structures */
+    bool parseZipArchive(void);
+
+    /* add a new entry to the hash table */
+    void addToHash(const char* str, int strLen, unsigned int hash);
+
+    /* compute string hash code */
+    static unsigned int computeHash(const char* str, int len);
+
+    /* convert a ZipEntryRO back to a hash table index */
+    int entryToIndex(const ZipEntryRO entry) const;
+
+    /*
+     * One entry in the hash table.
+     */
+    typedef struct HashEntry {
+        const char*     name;
+        unsigned short  nameLen;
+        //unsigned int    hash;
+    } HashEntry;
+
+    /* open Zip archive */
+    int         mFd;
+
+    /* Lock for handling the file descriptor (seeks, etc) */
+    mutable Mutex mFdLock;
+
+    /* zip file name */
+    char*       mFileName;
+
+    /* length of file */
+    size_t      mFileLength;
+
+    /* mapped file */
+    FileMap*    mDirectoryMap;
+
+    /* number of entries in the Zip archive */
+    int         mNumEntries;
+
+    /* CD directory offset in the Zip archive */
+    off64_t     mDirectoryOffset;
+
+    /*
+     * We know how many entries are in the Zip archive, so we have a
+     * fixed-size hash table.  We probe for an empty slot.
+     */
+    int         mHashTableSize;
+    HashEntry*  mHashTable;
+};
+
+}; // namespace android
+
+#endif /*__LIBS_ZIPFILERO_H*/
diff --git a/include/utils/ZipUtils.h b/include/utils/ZipUtils.h
new file mode 100644
index 0000000..42c42b6
--- /dev/null
+++ b/include/utils/ZipUtils.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// Miscellaneous zip/gzip utility functions.
+//
+#ifndef __LIBS_ZIPUTILS_H
+#define __LIBS_ZIPUTILS_H
+
+#include <stdio.h>
+
+namespace android {
+
+/*
+ * Container class for utility functions, primarily for namespace reasons.
+ */
+class ZipUtils {
+public:
+    /*
+     * General utility function for uncompressing "deflate" data from a file
+     * to a buffer.
+     */
+    static bool inflateToBuffer(int fd, void* buf, long uncompressedLen,
+        long compressedLen);
+    static bool inflateToBuffer(FILE* fp, void* buf, long uncompressedLen,
+        long compressedLen);
+
+    /*
+     * Someday we might want to make this generic and handle bzip2 ".bz2"
+     * files too.
+     *
+     * We could declare gzip to be a sub-class of zip that has exactly
+     * one always-compressed entry, but we currently want to treat Zip
+     * and gzip as distinct, so there's no value.
+     *
+     * The zlib library has some gzip utilities, but it has no interface
+     * for extracting the uncompressed length of the file (you do *not*
+     * want to gzseek to the end).
+     *
+     * Pass in a seeked file pointer for the gzip file.  If this is a gzip
+     * file, we set our return values appropriately and return "true" with
+     * the file seeked to the start of the compressed data.
+     */
+    static bool examineGzip(FILE* fp, int* pCompressionMethod,
+        long* pUncompressedLen, long* pCompressedLen, unsigned long* pCRC32);
+
+private:
+    ZipUtils() {}
+    ~ZipUtils() {}
+};
+
+}; // namespace android
+
+#endif /*__LIBS_ZIPUTILS_H*/
diff --git a/libs/utils/Android.mk b/libs/utils/Android.mk
index b4fc994..a5a59d8 100644
--- a/libs/utils/Android.mk
+++ b/libs/utils/Android.mk
@@ -42,6 +42,9 @@ commonSources:= \
 	Unicode.cpp \
 	VectorImpl.cpp \
 	WorkQueue.cpp \
+	ZipFileCRO.cpp \
+	ZipFileRO.cpp \
+	ZipUtils.cpp \
 	misc.cpp
 
 host_commonCflags := -DLIBUTILS_NATIVE=1 $(TOOL_CFLAGS)
@@ -96,7 +99,8 @@ LOCAL_LDLIBS += -lrt -ldl
 endif
 
 LOCAL_C_INCLUDES += \
-		bionic/libc/private
+		bionic/libc/private \
+		external/zlib
 
 LOCAL_LDLIBS += -lpthread
 
@@ -104,7 +108,8 @@ LOCAL_SHARED_LIBRARIES := \
 	liblog \
 	libcutils \
 	libdl \
-	libcorkscrew
+	libcorkscrew \
+	libz
 
 LOCAL_MODULE:= libutils
 include $(BUILD_SHARED_LIBRARY)
diff --git a/libs/utils/ZipFileCRO.cpp b/libs/utils/ZipFileCRO.cpp
new file mode 100644
index 0000000..55dfd9f
--- /dev/null
+++ b/libs/utils/ZipFileCRO.cpp
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <utils/ZipFileCRO.h>
+#include <utils/ZipFileRO.h>
+
+using namespace android;
+
+ZipFileCRO ZipFileXRO_open(const char* path) {
+    ZipFileRO* zip = new ZipFileRO();
+    if (zip->open(path) == NO_ERROR) {
+        return (ZipFileCRO)zip;
+    }
+    return NULL;
+}
+
+void ZipFileCRO_destroy(ZipFileCRO zipToken) {
+    ZipFileRO* zip = (ZipFileRO*)zipToken;
+    delete zip;
+}
+
+ZipEntryCRO ZipFileCRO_findEntryByName(ZipFileCRO zipToken,
+        const char* fileName) {
+    ZipFileRO* zip = (ZipFileRO*)zipToken;
+    return (ZipEntryCRO)zip->findEntryByName(fileName);
+}
+
+bool ZipFileCRO_getEntryInfo(ZipFileCRO zipToken, ZipEntryRO entryToken,
+        int* pMethod, size_t* pUncompLen,
+        size_t* pCompLen, off64_t* pOffset, long* pModWhen, long* pCrc32) {
+    ZipFileRO* zip = (ZipFileRO*)zipToken;
+    ZipEntryRO entry = (ZipEntryRO)entryToken;
+    return zip->getEntryInfo(entry, pMethod, pUncompLen, pCompLen, pOffset,
+            pModWhen, pCrc32);
+}
+
+bool ZipFileCRO_uncompressEntry(ZipFileCRO zipToken, ZipEntryRO entryToken, int fd) {
+    ZipFileRO* zip = (ZipFileRO*)zipToken;
+    ZipEntryRO entry = (ZipEntryRO)entryToken;
+    return zip->uncompressEntry(entry, fd);
+}
diff --git a/libs/utils/ZipFileRO.cpp b/libs/utils/ZipFileRO.cpp
new file mode 100644
index 0000000..cad7720
--- /dev/null
+++ b/libs/utils/ZipFileRO.cpp
@@ -0,0 +1,931 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// Read-only access to Zip archives, with minimal heap allocation.
+//
+#define LOG_TAG "zipro"
+//#define LOG_NDEBUG 0
+#include <utils/Log.h>
+#include <utils/ZipFileRO.h>
+#include <utils/misc.h>
+#include <utils/threads.h>
+
+#include <zlib.h>
+
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <assert.h>
+#include <unistd.h>
+
+#if HAVE_PRINTF_ZD
+#  define ZD "%zd"
+#  define ZD_TYPE ssize_t
+#else
+#  define ZD "%ld"
+#  define ZD_TYPE long
+#endif
+
+/*
+ * We must open binary files using open(path, ... | O_BINARY) under Windows.
+ * Otherwise strange read errors will happen.
+ */
+#ifndef O_BINARY
+#  define O_BINARY  0
+#endif
+
+/*
+ * TEMP_FAILURE_RETRY is defined by some, but not all, versions of
+ * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
+ * not already defined, then define it here.
+ */
+#ifndef TEMP_FAILURE_RETRY
+/* Used to retry syscalls that can return EINTR. */
+#define TEMP_FAILURE_RETRY(exp) ({         \
+    typeof (exp) _rc;                      \
+    do {                                   \
+        _rc = (exp);                       \
+    } while (_rc == -1 && errno == EINTR); \
+    _rc; })
+#endif
+
+using namespace android;
+
+/*
+ * Zip file constants.
+ */
+#define kEOCDSignature      0x06054b50
+#define kEOCDLen            22
+#define kEOCDNumEntries     8               // offset to #of entries in file
+#define kEOCDSize           12              // size of the central directory
+#define kEOCDFileOffset     16              // offset to central directory
+
+#define kMaxCommentLen      65535           // longest possible in ushort
+#define kMaxEOCDSearch      (kMaxCommentLen + kEOCDLen)
+
+#define kLFHSignature       0x04034b50
+#define kLFHLen             30              // excluding variable-len fields
+#define kLFHNameLen         26              // offset to filename length
+#define kLFHExtraLen        28              // offset to extra length
+
+#define kCDESignature       0x02014b50
+#define kCDELen             46              // excluding variable-len fields
+#define kCDEMethod          10              // offset to compression method
+#define kCDEModWhen         12              // offset to modification timestamp
+#define kCDECRC             16              // offset to entry CRC
+#define kCDECompLen         20              // offset to compressed length
+#define kCDEUncompLen       24              // offset to uncompressed length
+#define kCDENameLen         28              // offset to filename length
+#define kCDEExtraLen        30              // offset to extra length
+#define kCDECommentLen      32              // offset to comment length
+#define kCDELocalOffset     42              // offset to local hdr
+
+/*
+ * The values we return for ZipEntryRO use 0 as an invalid value, so we
+ * want to adjust the hash table index by a fixed amount.  Using a large
+ * value helps insure that people don't mix & match arguments, e.g. to
+ * findEntryByIndex().
+ */
+#define kZipEntryAdj        10000
+
+ZipFileRO::~ZipFileRO() {
+    free(mHashTable);
+    if (mDirectoryMap)
+        mDirectoryMap->release();
+    if (mFd >= 0)
+        TEMP_FAILURE_RETRY(close(mFd));
+    if (mFileName)
+        free(mFileName);
+}
+
+/*
+ * Convert a ZipEntryRO to a hash table index, verifying that it's in a
+ * valid range.
+ */
+int ZipFileRO::entryToIndex(const ZipEntryRO entry) const
+{
+    long ent = ((long) entry) - kZipEntryAdj;
+    if (ent < 0 || ent >= mHashTableSize || mHashTable[ent].name == NULL) {
+        ALOGW("Invalid ZipEntryRO %p (%ld)\n", entry, ent);
+        return -1;
+    }
+    return ent;
+}
+
+
+/*
+ * Open the specified file read-only.  We memory-map the entire thing and
+ * close the file before returning.
+ */
+status_t ZipFileRO::open(const char* zipFileName)
+{
+    int fd = -1;
+
+    assert(mDirectoryMap == NULL);
+
+    /*
+     * Open and map the specified file.
+     */
+    fd = ::open(zipFileName, O_RDONLY | O_BINARY);
+    if (fd < 0) {
+        ALOGW("Unable to open zip '%s': %s\n", zipFileName, strerror(errno));
+        return NAME_NOT_FOUND;
+    }
+
+    mFileLength = lseek64(fd, 0, SEEK_END);
+    if (mFileLength < kEOCDLen) {
+        TEMP_FAILURE_RETRY(close(fd));
+        return UNKNOWN_ERROR;
+    }
+
+    if (mFileName != NULL) {
+        free(mFileName);
+    }
+    mFileName = strdup(zipFileName);
+
+    mFd = fd;
+
+    /*
+     * Find the Central Directory and store its size and number of entries.
+     */
+    if (!mapCentralDirectory()) {
+        goto bail;
+    }
+
+    /*
+     * Verify Central Directory and create data structures for fast access.
+     */
+    if (!parseZipArchive()) {
+        goto bail;
+    }
+
+    return OK;
+
+bail:
+    free(mFileName);
+    mFileName = NULL;
+    TEMP_FAILURE_RETRY(close(fd));
+    return UNKNOWN_ERROR;
+}
+
+/*
+ * Parse the Zip archive, verifying its contents and initializing internal
+ * data structures.
+ */
+bool ZipFileRO::mapCentralDirectory(void)
+{
+    ssize_t readAmount = kMaxEOCDSearch;
+    if (readAmount > (ssize_t) mFileLength)
+        readAmount = mFileLength;
+
+    unsigned char* scanBuf = (unsigned char*) malloc(readAmount);
+    if (scanBuf == NULL) {
+        ALOGW("couldn't allocate scanBuf: %s", strerror(errno));
+        free(scanBuf);
+        return false;
+    }
+
+    /*
+     * Make sure this is a Zip archive.
+     */
+    if (lseek64(mFd, 0, SEEK_SET) != 0) {
+        ALOGW("seek to start failed: %s", strerror(errno));
+        free(scanBuf);
+        return false;
+    }
+
+    ssize_t actual = TEMP_FAILURE_RETRY(read(mFd, scanBuf, sizeof(int32_t)));
+    if (actual != (ssize_t) sizeof(int32_t)) {
+        ALOGI("couldn't read first signature from zip archive: %s", strerror(errno));
+        free(scanBuf);
+        return false;
+    }
+
+    {
+        unsigned int header = get4LE(scanBuf);
+        if (header == kEOCDSignature) {
+            ALOGI("Found Zip archive, but it looks empty\n");
+            free(scanBuf);
+            return false;
+        } else if (header != kLFHSignature) {
+            ALOGV("Not a Zip archive (found 0x%08x)\n", header);
+            free(scanBuf);
+            return false;
+        }
+    }
+
+    /*
+     * Perform the traditional EOCD snipe hunt.
+     *
+     * We're searching for the End of Central Directory magic number,
+     * which appears at the start of the EOCD block.  It's followed by
+     * 18 bytes of EOCD stuff and up to 64KB of archive comment.  We
+     * need to read the last part of the file into a buffer, dig through
+     * it to find the magic number, parse some values out, and use those
+     * to determine the extent of the CD.
+     *
+     * We start by pulling in the last part of the file.
+     */
+    off64_t searchStart = mFileLength - readAmount;
+
+    if (lseek64(mFd, searchStart, SEEK_SET) != searchStart) {
+        ALOGW("seek %ld failed: %s\n",  (long) searchStart, strerror(errno));
+        free(scanBuf);
+        return false;
+    }
+    actual = TEMP_FAILURE_RETRY(read(mFd, scanBuf, readAmount));
+    if (actual != (ssize_t) readAmount) {
+        ALOGW("Zip: read " ZD ", expected " ZD ". Failed: %s\n",
+            (ZD_TYPE) actual, (ZD_TYPE) readAmount, strerror(errno));
+        free(scanBuf);
+        return false;
+    }
+
+    /*
+     * Scan backward for the EOCD magic.  In an archive without a trailing
+     * comment, we'll find it on the first try.  (We may want to consider
+     * doing an initial minimal read; if we don't find it, retry with a
+     * second read as above.)
+     */
+    int i;
+    for (i = readAmount - kEOCDLen; i >= 0; i--) {
+        if (scanBuf[i] == 0x50 && get4LE(&scanBuf[i]) == kEOCDSignature) {
+            ALOGV("+++ Found EOCD at buf+%d\n", i);
+            break;
+        }
+    }
+    if (i < 0) {
+        ALOGD("Zip: EOCD not found, %s is not zip\n", mFileName);
+        free(scanBuf);
+        return false;
+    }
+
+    off64_t eocdOffset = searchStart + i;
+    const unsigned char* eocdPtr = scanBuf + i;
+
+    assert(eocdOffset < mFileLength);
+
+    /*
+     * Grab the CD offset and size, and the number of entries in the
+     * archive. After that, we can release our EOCD hunt buffer.
+     */
+    unsigned int numEntries = get2LE(eocdPtr + kEOCDNumEntries);
+    unsigned int dirSize = get4LE(eocdPtr + kEOCDSize);
+    unsigned int dirOffset = get4LE(eocdPtr + kEOCDFileOffset);
+    free(scanBuf);
+
+    // Verify that they look reasonable.
+    if ((long long) dirOffset + (long long) dirSize > (long long) eocdOffset) {
+        ALOGW("bad offsets (dir %ld, size %u, eocd %ld)\n",
+            (long) dirOffset, dirSize, (long) eocdOffset);
+        return false;
+    }
+    if (numEntries == 0) {
+        ALOGW("empty archive?\n");
+        return false;
+    }
+
+    ALOGV("+++ numEntries=%d dirSize=%d dirOffset=%d\n",
+        numEntries, dirSize, dirOffset);
+
+    mDirectoryMap = new FileMap();
+    if (mDirectoryMap == NULL) {
+        ALOGW("Unable to create directory map: %s", strerror(errno));
+        return false;
+    }
+
+    if (!mDirectoryMap->create(mFileName, mFd, dirOffset, dirSize, true)) {
+        ALOGW("Unable to map '%s' (" ZD " to " ZD "): %s\n", mFileName,
+                (ZD_TYPE) dirOffset, (ZD_TYPE) (dirOffset + dirSize), strerror(errno));
+        return false;
+    }
+
+    mNumEntries = numEntries;
+    mDirectoryOffset = dirOffset;
+
+    return true;
+}
+
+bool ZipFileRO::parseZipArchive(void)
+{
+    bool result = false;
+    const unsigned char* cdPtr = (const unsigned char*) mDirectoryMap->getDataPtr();
+    size_t cdLength = mDirectoryMap->getDataLength();
+    int numEntries = mNumEntries;
+
+    /*
+     * Create hash table.  We have a minimum 75% load factor, possibly as
+     * low as 50% after we round off to a power of 2.
+     */
+    mHashTableSize = roundUpPower2(1 + (numEntries * 4) / 3);
+    mHashTable = (HashEntry*) calloc(mHashTableSize, sizeof(HashEntry));
+
+    /*
+     * Walk through the central directory, adding entries to the hash
+     * table.
+     */
+    const unsigned char* ptr = cdPtr;
+    for (int i = 0; i < numEntries; i++) {
+        if (get4LE(ptr) != kCDESignature) {
+            ALOGW("Missed a central dir sig (at %d)\n", i);
+            goto bail;
+        }
+        if (ptr + kCDELen > cdPtr + cdLength) {
+            ALOGW("Ran off the end (at %d)\n", i);
+            goto bail;
+        }
+
+        long localHdrOffset = (long) get4LE(ptr + kCDELocalOffset);
+        if (localHdrOffset >= mDirectoryOffset) {
+            ALOGW("bad LFH offset %ld at entry %d\n", localHdrOffset, i);
+            goto bail;
+        }
+
+        unsigned int fileNameLen, extraLen, commentLen, hash;
+
+        fileNameLen = get2LE(ptr + kCDENameLen);
+        extraLen = get2LE(ptr + kCDEExtraLen);
+        commentLen = get2LE(ptr + kCDECommentLen);
+
+        /* add the CDE filename to the hash table */
+        hash = computeHash((const char*)ptr + kCDELen, fileNameLen);
+        addToHash((const char*)ptr + kCDELen, fileNameLen, hash);
+
+        ptr += kCDELen + fileNameLen + extraLen + commentLen;
+        if ((size_t)(ptr - cdPtr) > cdLength) {
+            ALOGW("bad CD advance (%d vs " ZD ") at entry %d\n",
+                (int) (ptr - cdPtr), (ZD_TYPE) cdLength, i);
+            goto bail;
+        }
+    }
+    ALOGV("+++ zip good scan %d entries\n", numEntries);
+    result = true;
+
+bail:
+    return result;
+}
+
+/*
+ * Simple string hash function for non-null-terminated strings.
+ */
+/*static*/ unsigned int ZipFileRO::computeHash(const char* str, int len)
+{
+    unsigned int hash = 0;
+
+    while (len--)
+        hash = hash * 31 + *str++;
+
+    return hash;
+}
+
+/*
+ * Add a new entry to the hash table.
+ */
+void ZipFileRO::addToHash(const char* str, int strLen, unsigned int hash)
+{
+    int ent = hash & (mHashTableSize-1);
+
+    /*
+     * We over-allocate the table, so we're guaranteed to find an empty slot.
+     */
+    while (mHashTable[ent].name != NULL)
+        ent = (ent + 1) & (mHashTableSize-1);
+
+    mHashTable[ent].name = str;
+    mHashTable[ent].nameLen = strLen;
+}
+
+/*
+ * Find a matching entry.
+ *
+ * Returns NULL if not found.
+ */
+ZipEntryRO ZipFileRO::findEntryByName(const char* fileName) const
+{
+    /*
+     * If the ZipFileRO instance is not initialized, the entry number will
+     * end up being garbage since mHashTableSize is -1.
+     */
+    if (mHashTableSize <= 0) {
+        return NULL;
+    }
+
+    int nameLen = strlen(fileName);
+    unsigned int hash = computeHash(fileName, nameLen);
+    int ent = hash & (mHashTableSize-1);
+
+    while (mHashTable[ent].name != NULL) {
+        if (mHashTable[ent].nameLen == nameLen &&
+            memcmp(mHashTable[ent].name, fileName, nameLen) == 0)
+        {
+            /* match */
+            return (ZipEntryRO)(long)(ent + kZipEntryAdj);
+        }
+
+        ent = (ent + 1) & (mHashTableSize-1);
+    }
+
+    return NULL;
+}
+
+/*
+ * Find the Nth entry.
+ *
+ * This currently involves walking through the sparse hash table, counting
+ * non-empty entries.  If we need to speed this up we can either allocate
+ * a parallel lookup table or (perhaps better) provide an iterator interface.
+ */
+ZipEntryRO ZipFileRO::findEntryByIndex(int idx) const
+{
+    if (idx < 0 || idx >= mNumEntries) {
+        ALOGW("Invalid index %d\n", idx);
+        return NULL;
+    }
+
+    for (int ent = 0; ent < mHashTableSize; ent++) {
+        if (mHashTable[ent].name != NULL) {
+            if (idx-- == 0)
+                return (ZipEntryRO) (ent + kZipEntryAdj);
+        }
+    }
+
+    return NULL;
+}
+
+/*
+ * Get the useful fields from the zip entry.
+ *
+ * Returns "false" if the offsets to the fields or the contents of the fields
+ * appear to be bogus.
+ */
+bool ZipFileRO::getEntryInfo(ZipEntryRO entry, int* pMethod, size_t* pUncompLen,
+    size_t* pCompLen, off64_t* pOffset, long* pModWhen, long* pCrc32) const
+{
+    bool ret = false;
+
+    const int ent = entryToIndex(entry);
+    if (ent < 0)
+        return false;
+
+    HashEntry hashEntry = mHashTable[ent];
+
+    /*
+     * Recover the start of the central directory entry from the filename
+     * pointer.  The filename is the first entry past the fixed-size data,
+     * so we can just subtract back from that.
+     */
+    const unsigned char* ptr = (const unsigned char*) hashEntry.name;
+    off64_t cdOffset = mDirectoryOffset;
+
+    ptr -= kCDELen;
+
+    int method = get2LE(ptr + kCDEMethod);
+    if (pMethod != NULL)
+        *pMethod = method;
+
+    if (pModWhen != NULL)
+        *pModWhen = get4LE(ptr + kCDEModWhen);
+    if (pCrc32 != NULL)
+        *pCrc32 = get4LE(ptr + kCDECRC);
+
+    size_t compLen = get4LE(ptr + kCDECompLen);
+    if (pCompLen != NULL)
+        *pCompLen = compLen;
+    size_t uncompLen = get4LE(ptr + kCDEUncompLen);
+    if (pUncompLen != NULL)
+        *pUncompLen = uncompLen;
+
+    /*
+     * If requested, determine the offset of the start of the data.  All we
+     * have is the offset to the Local File Header, which is variable size,
+     * so we have to read the contents of the struct to figure out where
+     * the actual data starts.
+     *
+     * We also need to make sure that the lengths are not so large that
+     * somebody trying to map the compressed or uncompressed data runs
+     * off the end of the mapped region.
+     *
+     * Note we don't verify compLen/uncompLen if they don't request the
+     * dataOffset, because dataOffset is expensive to determine.  However,
+     * if they don't have the file offset, they're not likely to be doing
+     * anything with the contents.
+     */
+    if (pOffset != NULL) {
+        long localHdrOffset = get4LE(ptr + kCDELocalOffset);
+        if (localHdrOffset + kLFHLen >= cdOffset) {
+            ALOGE("ERROR: bad local hdr offset in zip\n");
+            return false;
+        }
+
+        unsigned char lfhBuf[kLFHLen];
+
+#ifdef HAVE_PREAD
+        /*
+         * This file descriptor might be from zygote's preloaded assets,
+         * so we need to do an pread64() instead of a lseek64() + read() to
+         * guarantee atomicity across the processes with the shared file
+         * descriptors.
+         */
+        ssize_t actual =
+                TEMP_FAILURE_RETRY(pread64(mFd, lfhBuf, sizeof(lfhBuf), localHdrOffset));
+
+        if (actual != sizeof(lfhBuf)) {
+            ALOGW("failed reading lfh from offset %ld\n", localHdrOffset);
+            return false;
+        }
+
+        if (get4LE(lfhBuf) != kLFHSignature) {
+            ALOGW("didn't find signature at start of lfh; wanted: offset=%ld data=0x%08x; "
+                    "got: data=0x%08lx\n",
+                    localHdrOffset, kLFHSignature, get4LE(lfhBuf));
+            return false;
+        }
+#else /* HAVE_PREAD */
+        /*
+         * For hosts don't have pread64() we cannot guarantee atomic reads from
+         * an offset in a file. Android should never run on those platforms.
+         * File descriptors inherited from a fork() share file offsets and
+         * there would be nothing to protect from two different processes
+         * calling lseek64() concurrently.
+         */
+
+        {
+            AutoMutex _l(mFdLock);
+
+            if (lseek64(mFd, localHdrOffset, SEEK_SET) != localHdrOffset) {
+                ALOGW("failed seeking to lfh at offset %ld\n", localHdrOffset);
+                return false;
+            }
+
+            ssize_t actual =
+                    TEMP_FAILURE_RETRY(read(mFd, lfhBuf, sizeof(lfhBuf)));
+            if (actual != sizeof(lfhBuf)) {
+                ALOGW("failed reading lfh from offset %ld\n", localHdrOffset);
+                return false;
+            }
+
+            if (get4LE(lfhBuf) != kLFHSignature) {
+                off64_t actualOffset = lseek64(mFd, 0, SEEK_CUR);
+                ALOGW("didn't find signature at start of lfh; wanted: offset=%ld data=0x%08x; "
+                        "got: offset=" ZD " data=0x%08lx\n",
+                        localHdrOffset, kLFHSignature, (ZD_TYPE) actualOffset, get4LE(lfhBuf));
+                return false;
+            }
+        }
+#endif /* HAVE_PREAD */
+
+        off64_t dataOffset = localHdrOffset + kLFHLen
+            + get2LE(lfhBuf + kLFHNameLen) + get2LE(lfhBuf + kLFHExtraLen);
+        if (dataOffset >= cdOffset) {
+            ALOGW("bad data offset %ld in zip\n", (long) dataOffset);
+            return false;
+        }
+
+        /* check lengths */
+        if ((off64_t)(dataOffset + compLen) > cdOffset) {
+            ALOGW("bad compressed length in zip (%ld + " ZD " > %ld)\n",
+                (long) dataOffset, (ZD_TYPE) compLen, (long) cdOffset);
+            return false;
+        }
+
+        if (method == kCompressStored &&
+            (off64_t)(dataOffset + uncompLen) > cdOffset)
+        {
+            ALOGE("ERROR: bad uncompressed length in zip (%ld + " ZD " > %ld)\n",
+                (long) dataOffset, (ZD_TYPE) uncompLen, (long) cdOffset);
+            return false;
+        }
+
+        *pOffset = dataOffset;
+    }
+
+    return true;
+}
+
+/*
+ * Copy the entry's filename to the buffer.
+ */
+int ZipFileRO::getEntryFileName(ZipEntryRO entry, char* buffer, int bufLen)
+    const
+{
+    int ent = entryToIndex(entry);
+    if (ent < 0)
+        return -1;
+
+    int nameLen = mHashTable[ent].nameLen;
+    if (bufLen < nameLen+1)
+        return nameLen+1;
+
+    memcpy(buffer, mHashTable[ent].name, nameLen);
+    buffer[nameLen] = '\0';
+    return 0;
+}
+
+/*
+ * Create a new FileMap object that spans the data in "entry".
+ */
+FileMap* ZipFileRO::createEntryFileMap(ZipEntryRO entry) const
+{
+    /*
+     * TODO: the efficient way to do this is to modify FileMap to allow
+     * sub-regions of a file to be mapped.  A reference-counting scheme
+     * can manage the base memory mapping.  For now, we just create a brand
+     * new mapping off of the Zip archive file descriptor.
+     */
+
+    FileMap* newMap;
+    size_t compLen;
+    off64_t offset;
+
+    if (!getEntryInfo(entry, NULL, NULL, &compLen, &offset, NULL, NULL))
+        return NULL;
+
+    newMap = new FileMap();
+    if (!newMap->create(mFileName, mFd, offset, compLen, true)) {
+        newMap->release();
+        return NULL;
+    }
+
+    return newMap;
+}
+
+/*
+ * Uncompress an entry, in its entirety, into the provided output buffer.
+ *
+ * This doesn't verify the data's CRC, which might be useful for
+ * uncompressed data.  The caller should be able to manage it.
+ */
+bool ZipFileRO::uncompressEntry(ZipEntryRO entry, void* buffer) const
+{
+    const size_t kSequentialMin = 32768;
+    bool result = false;
+    int ent = entryToIndex(entry);
+    if (ent < 0)
+        return -1;
+
+    int method;
+    size_t uncompLen, compLen;
+    off64_t offset;
+    const unsigned char* ptr;
+
+    getEntryInfo(entry, &method, &uncompLen, &compLen, &offset, NULL, NULL);
+
+    FileMap* file = createEntryFileMap(entry);
+    if (file == NULL) {
+        goto bail;
+    }
+
+    ptr = (const unsigned char*) file->getDataPtr();
+
+    /*
+     * Experiment with madvise hint.  When we want to uncompress a file,
+     * we pull some stuff out of the central dir entry and then hit a
+     * bunch of compressed or uncompressed data sequentially.  The CDE
+     * visit will cause a limited amount of read-ahead because it's at
+     * the end of the file.  We could end up doing lots of extra disk
+     * access if the file we're prying open is small.  Bottom line is we
+     * probably don't want to turn MADV_SEQUENTIAL on and leave it on.
+     *
+     * So, if the compressed size of the file is above a certain minimum
+     * size, temporarily boost the read-ahead in the hope that the extra
+     * pair of system calls are negated by a reduction in page faults.
+     */
+    if (compLen > kSequentialMin)
+        file->advise(FileMap::SEQUENTIAL);
+
+    if (method == kCompressStored) {
+        memcpy(buffer, ptr, uncompLen);
+    } else {
+        if (!inflateBuffer(buffer, ptr, uncompLen, compLen))
+            goto unmap;
+    }
+
+    if (compLen > kSequentialMin)
+        file->advise(FileMap::NORMAL);
+
+    result = true;
+
+unmap:
+    file->release();
+bail:
+    return result;
+}
+
+/*
+ * Uncompress an entry, in its entirety, to an open file descriptor.
+ *
+ * This doesn't verify the data's CRC, but probably should.
+ */
+bool ZipFileRO::uncompressEntry(ZipEntryRO entry, int fd) const
+{
+    bool result = false;
+    int ent = entryToIndex(entry);
+    if (ent < 0)
+        return -1;
+
+    int method;
+    size_t uncompLen, compLen;
+    off64_t offset;
+    const unsigned char* ptr;
+
+    getEntryInfo(entry, &method, &uncompLen, &compLen, &offset, NULL, NULL);
+
+    FileMap* file = createEntryFileMap(entry);
+    if (file == NULL) {
+        goto bail;
+    }
+
+    ptr = (const unsigned char*) file->getDataPtr();
+
+    if (method == kCompressStored) {
+        ssize_t actual = write(fd, ptr, uncompLen);
+        if (actual < 0) {
+            ALOGE("Write failed: %s\n", strerror(errno));
+            goto unmap;
+        } else if ((size_t) actual != uncompLen) {
+            ALOGE("Partial write during uncompress (" ZD " of " ZD ")\n",
+                (ZD_TYPE) actual, (ZD_TYPE) uncompLen);
+            goto unmap;
+        } else {
+            ALOGI("+++ successful write\n");
+        }
+    } else {
+        if (!inflateBuffer(fd, ptr, uncompLen, compLen))
+            goto unmap;
+    }
+
+    result = true;
+
+unmap:
+    file->release();
+bail:
+    return result;
+}
+
+/*
+ * Uncompress "deflate" data from one buffer to another.
+ */
+/*static*/ bool ZipFileRO::inflateBuffer(void* outBuf, const void* inBuf,
+    size_t uncompLen, size_t compLen)
+{
+    bool result = false;
+    z_stream zstream;
+    int zerr;
+
+    /*
+     * Initialize the zlib stream struct.
+     */
+    memset(&zstream, 0, sizeof(zstream));
+    zstream.zalloc = Z_NULL;
+    zstream.zfree = Z_NULL;
+    zstream.opaque = Z_NULL;
+    zstream.next_in = (Bytef*)inBuf;
+    zstream.avail_in = compLen;
+    zstream.next_out = (Bytef*) outBuf;
+    zstream.avail_out = uncompLen;
+    zstream.data_type = Z_UNKNOWN;
+
+    /*
+     * Use the undocumented "negative window bits" feature to tell zlib
+     * that there's no zlib header waiting for it.
+     */
+    zerr = inflateInit2(&zstream, -MAX_WBITS);
+    if (zerr != Z_OK) {
+        if (zerr == Z_VERSION_ERROR) {
+            ALOGE("Installed zlib is not compatible with linked version (%s)\n",
+                ZLIB_VERSION);
+        } else {
+            ALOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr);
+        }
+        goto bail;
+    }
+
+    /*
+     * Expand data.
+     */
+    zerr = inflate(&zstream, Z_FINISH);
+    if (zerr != Z_STREAM_END) {
+        ALOGW("Zip inflate failed, zerr=%d (nIn=%p aIn=%u nOut=%p aOut=%u)\n",
+            zerr, zstream.next_in, zstream.avail_in,
+            zstream.next_out, zstream.avail_out);
+        goto z_bail;
+    }
+
+    /* paranoia */
+    if (zstream.total_out != uncompLen) {
+        ALOGW("Size mismatch on inflated file (%ld vs " ZD ")\n",
+            zstream.total_out, (ZD_TYPE) uncompLen);
+        goto z_bail;
+    }
+
+    result = true;
+
+z_bail:
+    inflateEnd(&zstream);        /* free up any allocated structures */
+
+bail:
+    return result;
+}
+
+/*
+ * Uncompress "deflate" data from one buffer to an open file descriptor.
+ */
+/*static*/ bool ZipFileRO::inflateBuffer(int fd, const void* inBuf,
+    size_t uncompLen, size_t compLen)
+{
+    bool result = false;
+    const size_t kWriteBufSize = 32768;
+    unsigned char writeBuf[kWriteBufSize];
+    z_stream zstream;
+    int zerr;
+
+    /*
+     * Initialize the zlib stream struct.
+     */
+    memset(&zstream, 0, sizeof(zstream));
+    zstream.zalloc = Z_NULL;
+    zstream.zfree = Z_NULL;
+    zstream.opaque = Z_NULL;
+    zstream.next_in = (Bytef*)inBuf;
+    zstream.avail_in = compLen;
+    zstream.next_out = (Bytef*) writeBuf;
+    zstream.avail_out = sizeof(writeBuf);
+    zstream.data_type = Z_UNKNOWN;
+
+    /*
+     * Use the undocumented "negative window bits" feature to tell zlib
+     * that there's no zlib header waiting for it.
+     */
+    zerr = inflateInit2(&zstream, -MAX_WBITS);
+    if (zerr != Z_OK) {
+        if (zerr == Z_VERSION_ERROR) {
+            ALOGE("Installed zlib is not compatible with linked version (%s)\n",
+                ZLIB_VERSION);
+        } else {
+            ALOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr);
+        }
+        goto bail;
+    }
+
+    /*
+     * Loop while we have more to do.
+     */
+    do {
+        /*
+         * Expand data.
+         */
+        zerr = inflate(&zstream, Z_NO_FLUSH);
+        if (zerr != Z_OK && zerr != Z_STREAM_END) {
+            ALOGW("zlib inflate: zerr=%d (nIn=%p aIn=%u nOut=%p aOut=%u)\n",
+                zerr, zstream.next_in, zstream.avail_in,
+                zstream.next_out, zstream.avail_out);
+            goto z_bail;
+        }
+
+        /* write when we're full or when we're done */
+        if (zstream.avail_out == 0 ||
+            (zerr == Z_STREAM_END && zstream.avail_out != sizeof(writeBuf)))
+        {
+            long writeSize = zstream.next_out - writeBuf;
+            int cc = write(fd, writeBuf, writeSize);
+            if (cc != (int) writeSize) {
+                ALOGW("write failed in inflate (%d vs %ld)\n", cc, writeSize);
+                goto z_bail;
+            }
+
+            zstream.next_out = writeBuf;
+            zstream.avail_out = sizeof(writeBuf);
+        }
+    } while (zerr == Z_OK);
+
+    assert(zerr == Z_STREAM_END);       /* other errors should've been caught */
+
+    /* paranoia */
+    if (zstream.total_out != uncompLen) {
+        ALOGW("Size mismatch on inflated file (%ld vs " ZD ")\n",
+            zstream.total_out, (ZD_TYPE) uncompLen);
+        goto z_bail;
+    }
+
+    result = true;
+
+z_bail:
+    inflateEnd(&zstream);        /* free up any allocated structures */
+
+bail:
+    return result;
+}
diff --git a/libs/utils/ZipUtils.cpp b/libs/utils/ZipUtils.cpp
new file mode 100644
index 0000000..cf5467b
--- /dev/null
+++ b/libs/utils/ZipUtils.cpp
@@ -0,0 +1,343 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// Misc zip/gzip utility functions.
+//
+
+#define LOG_TAG "ziputil"
+
+#include <utils/Log.h>
+#include <utils/ZipUtils.h>
+#include <utils/ZipFileRO.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <zlib.h>
+
+using namespace android;
+
+/*
+ * Utility function that expands zip/gzip "deflate" compressed data
+ * into a buffer.
+ *
+ * "fd" is an open file positioned at the start of the "deflate" data
+ * "buf" must hold at least "uncompressedLen" bytes.
+ */
+/*static*/ bool ZipUtils::inflateToBuffer(int fd, void* buf,
+    long uncompressedLen, long compressedLen)
+{
+    bool result = false;
+	const unsigned long kReadBufSize = 32768;
+	unsigned char* readBuf = NULL;
+    z_stream zstream;
+    int zerr;
+    unsigned long compRemaining;
+
+    assert(uncompressedLen >= 0);
+    assert(compressedLen >= 0);
+
+	readBuf = new unsigned char[kReadBufSize];
+	if (readBuf == NULL)
+        goto bail;
+    compRemaining = compressedLen;
+
+    /*
+     * Initialize the zlib stream.
+     */
+	memset(&zstream, 0, sizeof(zstream));
+    zstream.zalloc = Z_NULL;
+    zstream.zfree = Z_NULL;
+    zstream.opaque = Z_NULL;
+    zstream.next_in = NULL;
+    zstream.avail_in = 0;
+    zstream.next_out = (Bytef*) buf;
+    zstream.avail_out = uncompressedLen;
+    zstream.data_type = Z_UNKNOWN;
+
+	/*
+	 * Use the undocumented "negative window bits" feature to tell zlib
+	 * that there's no zlib header waiting for it.
+	 */
+    zerr = inflateInit2(&zstream, -MAX_WBITS);
+    if (zerr != Z_OK) {
+        if (zerr == Z_VERSION_ERROR) {
+            ALOGE("Installed zlib is not compatible with linked version (%s)\n",
+                ZLIB_VERSION);
+        } else {
+            ALOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr);
+        }
+        goto bail;
+    }
+
+    /*
+     * Loop while we have data.
+     */
+    do {
+        unsigned long getSize;
+
+        /* read as much as we can */
+        if (zstream.avail_in == 0) {
+            getSize = (compRemaining > kReadBufSize) ?
+                        kReadBufSize : compRemaining;
+            ALOGV("+++ reading %ld bytes (%ld left)\n",
+                getSize, compRemaining);
+
+            int cc = read(fd, readBuf, getSize);
+            if (cc != (int) getSize) {
+                ALOGD("inflate read failed (%d vs %ld)\n",
+                    cc, getSize);
+                goto z_bail;
+            }
+
+            compRemaining -= getSize;
+
+            zstream.next_in = readBuf;
+            zstream.avail_in = getSize;
+        }
+
+        /* uncompress the data */
+        zerr = inflate(&zstream, Z_NO_FLUSH);
+        if (zerr != Z_OK && zerr != Z_STREAM_END) {
+            ALOGD("zlib inflate call failed (zerr=%d)\n", zerr);
+            goto z_bail;
+        }
+
+		/* output buffer holds all, so no need to write the output */
+    } while (zerr == Z_OK);
+
+    assert(zerr == Z_STREAM_END);       /* other errors should've been caught */
+
+    if ((long) zstream.total_out != uncompressedLen) {
+        ALOGW("Size mismatch on inflated file (%ld vs %ld)\n",
+            zstream.total_out, uncompressedLen);
+        goto z_bail;
+    }
+
+    // success!
+    result = true;
+
+z_bail:
+    inflateEnd(&zstream);        /* free up any allocated structures */
+
+bail:
+	delete[] readBuf;
+    return result;
+}
+
+/*
+ * Utility function that expands zip/gzip "deflate" compressed data
+ * into a buffer.
+ *
+ * (This is a clone of the previous function, but it takes a FILE* instead
+ * of an fd.  We could pass fileno(fd) to the above, but we can run into
+ * trouble when "fp" has a different notion of what fd's file position is.)
+ *
+ * "fp" is an open file positioned at the start of the "deflate" data
+ * "buf" must hold at least "uncompressedLen" bytes.
+ */
+/*static*/ bool ZipUtils::inflateToBuffer(FILE* fp, void* buf,
+    long uncompressedLen, long compressedLen)
+{
+    bool result = false;
+	const unsigned long kReadBufSize = 32768;
+	unsigned char* readBuf = NULL;
+    z_stream zstream;
+    int zerr;
+    unsigned long compRemaining;
+
+    assert(uncompressedLen >= 0);
+    assert(compressedLen >= 0);
+
+	readBuf = new unsigned char[kReadBufSize];
+	if (readBuf == NULL)
+        goto bail;
+    compRemaining = compressedLen;
+
+    /*
+     * Initialize the zlib stream.
+     */
+	memset(&zstream, 0, sizeof(zstream));
+    zstream.zalloc = Z_NULL;
+    zstream.zfree = Z_NULL;
+    zstream.opaque = Z_NULL;
+    zstream.next_in = NULL;
+    zstream.avail_in = 0;
+    zstream.next_out = (Bytef*) buf;
+    zstream.avail_out = uncompressedLen;
+    zstream.data_type = Z_UNKNOWN;
+
+	/*
+	 * Use the undocumented "negative window bits" feature to tell zlib
+	 * that there's no zlib header waiting for it.
+	 */
+    zerr = inflateInit2(&zstream, -MAX_WBITS);
+    if (zerr != Z_OK) {
+        if (zerr == Z_VERSION_ERROR) {
+            ALOGE("Installed zlib is not compatible with linked version (%s)\n",
+                ZLIB_VERSION);
+        } else {
+            ALOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr);
+        }
+        goto bail;
+    }
+
+    /*
+     * Loop while we have data.
+     */
+    do {
+        unsigned long getSize;
+
+        /* read as much as we can */
+        if (zstream.avail_in == 0) {
+            getSize = (compRemaining > kReadBufSize) ?
+                        kReadBufSize : compRemaining;
+            ALOGV("+++ reading %ld bytes (%ld left)\n",
+                getSize, compRemaining);
+
+            int cc = fread(readBuf, 1, getSize, fp);
+            if (cc != (int) getSize) {
+                ALOGD("inflate read failed (%d vs %ld)\n",
+                    cc, getSize);
+                goto z_bail;
+            }
+
+            compRemaining -= getSize;
+
+            zstream.next_in = readBuf;
+            zstream.avail_in = getSize;
+        }
+
+        /* uncompress the data */
+        zerr = inflate(&zstream, Z_NO_FLUSH);
+        if (zerr != Z_OK && zerr != Z_STREAM_END) {
+            ALOGD("zlib inflate call failed (zerr=%d)\n", zerr);
+            goto z_bail;
+        }
+
+		/* output buffer holds all, so no need to write the output */
+    } while (zerr == Z_OK);
+
+    assert(zerr == Z_STREAM_END);       /* other errors should've been caught */
+
+    if ((long) zstream.total_out != uncompressedLen) {
+        ALOGW("Size mismatch on inflated file (%ld vs %ld)\n",
+            zstream.total_out, uncompressedLen);
+        goto z_bail;
+    }
+
+    // success!
+    result = true;
+
+z_bail:
+    inflateEnd(&zstream);        /* free up any allocated structures */
+
+bail:
+	delete[] readBuf;
+    return result;
+}
+
+/*
+ * Look at the contents of a gzip archive.  We want to know where the
+ * data starts, and how long it will be after it is uncompressed.
+ *
+ * We expect to find the CRC and length as the last 8 bytes on the file.
+ * This is a pretty reasonable thing to expect for locally-compressed
+ * files, but there's a small chance that some extra padding got thrown
+ * on (the man page talks about compressed data written to tape).  We
+ * don't currently deal with that here.  If "gzip -l" whines, we're going
+ * to fail too.
+ *
+ * On exit, "fp" is pointing at the start of the compressed data.
+ */
+/*static*/ bool ZipUtils::examineGzip(FILE* fp, int* pCompressionMethod,
+    long* pUncompressedLen, long* pCompressedLen, unsigned long* pCRC32)
+{
+    enum {  // flags
+        FTEXT       = 0x01,
+        FHCRC       = 0x02,
+        FEXTRA      = 0x04,
+        FNAME       = 0x08,
+        FCOMMENT    = 0x10,
+    };
+    int ic;
+    int method, flags;
+    int i;
+
+    ic = getc(fp);
+    if (ic != 0x1f || getc(fp) != 0x8b)
+        return false;       // not gzip
+    method = getc(fp);
+    flags = getc(fp);
+
+    /* quick sanity checks */
+    if (method == EOF || flags == EOF)
+        return false;
+    if (method != ZipFileRO::kCompressDeflated)
+        return false;
+
+    /* skip over 4 bytes of mod time, 1 byte XFL, 1 byte OS */
+    for (i = 0; i < 6; i++)
+        (void) getc(fp);
+    /* consume "extra" field, if present */
+    if ((flags & FEXTRA) != 0) {
+        int len;
+
+        len = getc(fp);
+        len |= getc(fp) << 8;
+        while (len-- && getc(fp) != EOF)
+            ;
+    }
+    /* consume filename, if present */
+    if ((flags & FNAME) != 0) {
+        do {
+            ic = getc(fp);
+        } while (ic != 0 && ic != EOF);
+    }
+    /* consume comment, if present */
+    if ((flags & FCOMMENT) != 0) {
+        do {
+            ic = getc(fp);
+        } while (ic != 0 && ic != EOF);
+    }
+    /* consume 16-bit header CRC, if present */
+    if ((flags & FHCRC) != 0) {
+        (void) getc(fp);
+        (void) getc(fp);
+    }
+
+    if (feof(fp) || ferror(fp))
+        return false;
+
+    /* seek to the end; CRC and length are in the last 8 bytes */
+    long curPosn = ftell(fp);
+    unsigned char buf[8];
+    fseek(fp, -8, SEEK_END);
+    *pCompressedLen = ftell(fp) - curPosn;
+
+    if (fread(buf, 1, 8, fp) != 8)
+        return false;
+    /* seek back to start of compressed data */
+    fseek(fp, curPosn, SEEK_SET);
+
+    *pCompressionMethod = method;
+    *pCRC32 = ZipFileRO::get4LE(&buf[0]);
+    *pUncompressedLen = ZipFileRO::get4LE(&buf[4]);
+
+    return true;
+}
diff --git a/libs/utils/tests/Android.mk b/libs/utils/tests/Android.mk
index a6811fc..98e4936 100644
--- a/libs/utils/tests/Android.mk
+++ b/libs/utils/tests/Android.mk
@@ -9,6 +9,7 @@ test_src_files := \
 	Looper_test.cpp \
 	String8_test.cpp \
 	Unicode_test.cpp \
+	ZipFileRO_test.cpp
 
 shared_libraries := \
 	libz \
diff --git a/libs/utils/tests/ZipFileRO_test.cpp b/libs/utils/tests/ZipFileRO_test.cpp
new file mode 100644
index 0000000..7a1d0bd
--- /dev/null
+++ b/libs/utils/tests/ZipFileRO_test.cpp
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "ZipFileRO_test"
+#include <utils/Log.h>
+#include <utils/ZipFileRO.h>
+
+#include <gtest/gtest.h>
+
+#include <fcntl.h>
+#include <string.h>
+
+namespace android {
+
+class ZipFileROTest : public testing::Test {
+protected:
+    virtual void SetUp() {
+    }
+
+    virtual void TearDown() {
+    }
+};
+
+TEST_F(ZipFileROTest, ZipTimeConvertSuccess) {
+    struct tm t;
+
+    // 2011-06-29 14:40:40
+    long when = 0x3EDD7514;
+
+    ZipFileRO::zipTimeToTimespec(when, &t);
+
+    EXPECT_EQ(2011, t.tm_year + 1900)
+            << "Year was improperly converted.";
+
+    EXPECT_EQ(6, t.tm_mon)
+            << "Month was improperly converted.";
+
+    EXPECT_EQ(29, t.tm_mday)
+            << "Day was improperly converted.";
+
+    EXPECT_EQ(14, t.tm_hour)
+            << "Hour was improperly converted.";
+
+    EXPECT_EQ(40, t.tm_min)
+            << "Minute was improperly converted.";
+
+    EXPECT_EQ(40, t.tm_sec)
+            << "Second was improperly converted.";
+}
+
+}