diff --git a/modules/camera/Metadata.cpp b/modules/camera/Metadata.cpp
index ba7ed9c..72314d5 100644
--- a/modules/camera/Metadata.cpp
+++ b/modules/camera/Metadata.cpp
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-#include <pthread.h>
 #include <system/camera_metadata.h>
 
 //#define LOG_NDEBUG 0
@@ -28,95 +27,79 @@
 
 namespace default_camera_hal {
 
-Metadata::Metadata()
-  : mHead(NULL),
-    mTail(NULL),
-    mEntryCount(0),
-    mDataCount(0),
-    mGenerated(NULL),
-    mDirty(true)
+Metadata::Metadata():
+    mData(NULL)
 {
-    // NULL (default) pthread mutex attributes
-    pthread_mutex_init(&mMutex, NULL);
 }
 
 Metadata::~Metadata()
 {
-    Entry *current = mHead;
-
-    while (current != NULL) {
-        Entry *tmp = current;
-        current = current->mNext;
-        delete tmp;
-    }
-
-    if (mGenerated != NULL)
-        free_camera_metadata(mGenerated);
-
-    pthread_mutex_destroy(&mMutex);
+    replace(NULL);
 }
 
-Metadata::Metadata(uint8_t mode, uint8_t intent)
-  : mHead(NULL),
-    mTail(NULL),
-    mEntryCount(0),
-    mDataCount(0),
-    mGenerated(NULL),
-    mDirty(true)
+void Metadata::replace(camera_metadata_t *m)
 {
-    pthread_mutex_init(&mMutex, NULL);
-
-    if (validate(ANDROID_CONTROL_MODE, TYPE_BYTE, 1)) {
-        int res = add(ANDROID_CONTROL_MODE, 1, &mode);
-        if (res != 0) {
-            ALOGE("%s: Unable to add mode to template!", __func__);
-        }
-    } else {
-        ALOGE("%s: Invalid mode constructing template!", __func__);
+    if (m == mData) {
+        ALOGE("%s: Replacing metadata with itself?!", __func__);
+        return;
     }
-
-    if (validate(ANDROID_CONTROL_CAPTURE_INTENT, TYPE_BYTE, 1)) {
-        int res = add(ANDROID_CONTROL_CAPTURE_INTENT, 1, &intent);
-        if (res != 0) {
-            ALOGE("%s: Unable to add capture intent to template!", __func__);
-        }
-    } else {
-        ALOGE("%s: Invalid capture intent constructing template!", __func__);
-    }
+    if (mData)
+        free_camera_metadata(mData);
+    mData = m;
 }
 
-int Metadata::addUInt8(uint32_t tag, int count, uint8_t *data)
+int Metadata::init(const camera_metadata_t *metadata)
+{
+    camera_metadata_t* tmp;
+
+    if (!validate_camera_metadata_structure(metadata, NULL))
+        return -EINVAL;
+
+    tmp = clone_camera_metadata(metadata);
+    if (tmp == NULL)
+        return -EINVAL;
+
+    replace(tmp);
+    return 0;
+}
+
+int Metadata::addUInt8(uint32_t tag, int count, const uint8_t *data)
 {
     if (!validate(tag, TYPE_BYTE, count)) return -EINVAL;
     return add(tag, count, data);
 }
 
-int Metadata::addInt32(uint32_t tag, int count, int32_t *data)
+int Metadata::add1UInt8(uint32_t tag, const uint8_t data)
+{
+    return addUInt8(tag, 1, &data);
+}
+
+int Metadata::addInt32(uint32_t tag, int count, const int32_t *data)
 {
     if (!validate(tag, TYPE_INT32, count)) return -EINVAL;
     return add(tag, count, data);
 }
 
-int Metadata::addFloat(uint32_t tag, int count, float *data)
+int Metadata::addFloat(uint32_t tag, int count, const float *data)
 {
     if (!validate(tag, TYPE_FLOAT, count)) return -EINVAL;
     return add(tag, count, data);
 }
 
-int Metadata::addInt64(uint32_t tag, int count, int64_t *data)
+int Metadata::addInt64(uint32_t tag, int count, const int64_t *data)
 {
     if (!validate(tag, TYPE_INT64, count)) return -EINVAL;
     return add(tag, count, data);
 }
 
-int Metadata::addDouble(uint32_t tag, int count, double *data)
+int Metadata::addDouble(uint32_t tag, int count, const double *data)
 {
     if (!validate(tag, TYPE_DOUBLE, count)) return -EINVAL;
     return add(tag, count, data);
 }
 
 int Metadata::addRational(uint32_t tag, int count,
-        camera_metadata_rational_t *data)
+        const camera_metadata_rational_t *data)
 {
     if (!validate(tag, TYPE_RATIONAL, count)) return -EINVAL;
     return add(tag, count, data);
@@ -144,102 +127,46 @@
     return true;
 }
 
-int Metadata::add(uint32_t tag, int count, void *tag_data)
+int Metadata::add(uint32_t tag, int count, const void *tag_data)
 {
+    int res;
+    camera_metadata_t* tmp;
     int tag_type = get_camera_metadata_tag_type(tag);
-    size_t type_sz = camera_metadata_type_size[tag_type];
+    size_t size = calculate_camera_metadata_entry_data_size(tag_type, count);
+    size_t entry_capacity = get_camera_metadata_entry_count(mData) + 1;
+    size_t data_capacity = get_camera_metadata_data_count(mData) + size;
 
-    // Allocate array to hold new metadata
-    void *data = malloc(count * type_sz);
-    if (data == NULL)
+    // Opportunistically attempt to add if metadata has room for it
+    if (!add_camera_metadata_entry(mData, tag, tag_data, count))
+        return 0;
+
+    // Double new dimensions to minimize future reallocations
+    tmp = allocate_camera_metadata(entry_capacity * 2, data_capacity * 2);
+    if (tmp == NULL) {
+        ALOGE("%s: Failed to allocate new metadata with %d entries, %d data",
+                __func__, entry_capacity, data_capacity);
         return -ENOMEM;
-    memcpy(data, tag_data, count * type_sz);
+    }
+    // Append the current metadata to the new (empty) metadata
+    if (res = append_camera_metadata(tmp, mData)) {
+        ALOGE("%s: Failed to append old metadata %p to new %p",
+                __func__, mData, tmp);
+        return res;
+    }
+    // Add the remaining new item
+    if (res = add_camera_metadata_entry(tmp, tag, tag_data, count)) {
+        ALOGE("%s: Failed to add new entry (%d, %p, %d) to metadata %p",
+                __func__, tag, tag_data, count, tmp);
+        return res;
+    }
 
-    pthread_mutex_lock(&mMutex);
-    mEntryCount++;
-    mDataCount += calculate_camera_metadata_entry_data_size(tag_type, count);
-    push(new Entry(tag, data, count));
-    mDirty = true;
-    pthread_mutex_unlock(&mMutex);
+    replace(tmp);
     return 0;
 }
 
-camera_metadata_t* Metadata::generate()
+camera_metadata_t* Metadata::get()
 {
-    pthread_mutex_lock(&mMutex);
-    // Reuse if old generated metadata still valid
-    if (!mDirty && mGenerated != NULL) {
-        ALOGV("%s: Reusing generated metadata at %p", __func__, mGenerated);
-        goto out;
-    }
-    // Destroy old metadata
-    if (mGenerated != NULL) {
-        ALOGV("%s: Freeing generated metadata at %p", __func__, mGenerated);
-        free_camera_metadata(mGenerated);
-        mGenerated = NULL;
-    }
-    // Generate new metadata structure
-    ALOGV("%s: Generating new camera metadata structure, Entries:%d Data:%d",
-            __func__, mEntryCount, mDataCount);
-    mGenerated = allocate_camera_metadata(mEntryCount, mDataCount);
-    if (mGenerated == NULL) {
-        ALOGE("%s: Failed to allocate metadata (%d entries %d data)",
-                __func__, mEntryCount, mDataCount);
-        goto out;
-    }
-    // Walk list of entries adding each one to newly allocated metadata
-    for (Entry *current = mHead; current != NULL; current = current->mNext) {
-        int res = add_camera_metadata_entry(mGenerated, current->mTag,
-                current->mData, current->mCount);
-        if (res != 0) {
-            ALOGE("%s: Failed to add camera metadata: %d", __func__, res);
-            free_camera_metadata(mGenerated);
-            mGenerated = NULL;
-            goto out;
-        }
-    }
-
-out:
-    pthread_mutex_unlock(&mMutex);
-    return mGenerated;
-}
-
-Metadata::Entry::Entry(uint32_t tag, void *data, int count)
-  : mNext(NULL),
-    mPrev(NULL),
-    mTag(tag),
-    mData(data),
-    mCount(count)
-{
-}
-
-void Metadata::push(Entry *e)
-{
-    if (mHead == NULL) {
-        mHead = mTail = e;
-    } else {
-        mTail->insertAfter(e);
-        mTail = e;
-    }
-}
-
-Metadata::Entry::~Entry()
-{
-    if (mNext != NULL)
-        mNext->mPrev = mPrev;
-    if (mPrev != NULL)
-        mPrev->mNext = mNext;
-}
-
-void Metadata::Entry::insertAfter(Entry *e)
-{
-    if (e == NULL)
-        return;
-    if (mNext != NULL)
-        mNext->mPrev = e;
-    e->mNext = mNext;
-    e->mPrev = this;
-    mNext = e;
+    return mData;
 }
 
 } // namespace default_camera_hal