Further work on libmediametrics stable API

implement a missing method (for inflight metrics), enumerate exported
symbols.

Bug: 119675363
Test: build, CTS media/codec tests
Change-Id: Id92f1b331babacc0de6c0005d6ba0c97c91c0291

media/libmediametrics/Android.bp

@@ -1,6 +1,4 @@
-// TODO: change it back to cc_library_shared when there is a way to
-// expose media metrics as stable API.
-cc_library {
+cc_library_shared {
     name: "libmediametrics",
 
     srcs: [
@@ -32,12 +30,13 @@ cc_library {
         cfi: true,
     },
 
-    // enumerate the stable interface
-// this would mean nobody can use the C++ interface. have to rework some things.
-//  stubs: {
-//      symbol_file: "libmediametrics.map.txt",
-//      versions: [
-//          "1" ,
-//      ]
-//  },
+    // enumerate stable entry points, for apex use
+    stubs: {
+        symbol_file: "libmediametrics.map.txt",
+        versions: [
+            "1" ,
+        ]
+    },
 }
+
+

media/libmediametrics/IMediaAnalyticsService.cpp

@@ -142,7 +142,7 @@ status_t BnMediaAnalyticsService::onTransact(
             CHECK_INTERFACE(IMediaAnalyticsService, data, reply);
 
             bool forcenew;
-            MediaAnalyticsItem *item = new MediaAnalyticsItem;
+            MediaAnalyticsItem *item = MediaAnalyticsItem::create();
 
             data.readBool(&forcenew);
             item->readFromParcel(data);

media/libmediametrics/MediaAnalyticsItem.cpp

@@ -52,6 +52,17 @@ const char * const MediaAnalyticsItem::EnabledProperty  = "media.metrics.enabled
 const char * const MediaAnalyticsItem::EnabledPropertyPersist  = "persist.media.metrics.enabled";
 const int MediaAnalyticsItem::EnabledProperty_default  = 1;
 
+// So caller doesn't need to know size of allocated space
+MediaAnalyticsItem *MediaAnalyticsItem::create()
+{
+    return MediaAnalyticsItem::create(kKeyNone);
+}
+
+MediaAnalyticsItem *MediaAnalyticsItem::create(MediaAnalyticsItem::Key key)
+{
+    MediaAnalyticsItem *item = new MediaAnalyticsItem(key);
+    return item;
+}
 
 // access functions for the class
 MediaAnalyticsItem::MediaAnalyticsItem()
@@ -642,6 +653,19 @@ bool MediaAnalyticsItem::growProps(int increment)
 //
 
 int32_t MediaAnalyticsItem::readFromParcel(const Parcel& data) {
+    int32_t version = data.readInt32();
+
+    switch(version) {
+        case 0:
+          return readFromParcel0(data);
+          break;
+        default:
+          ALOGE("Unsupported MediaAnalyticsItem Parcel version: %d", version);
+          return -1;
+    }
+}
+
+int32_t MediaAnalyticsItem::readFromParcel0(const Parcel& data) {
     // into 'this' object
     // .. we make a copy of the string to put away.
     mKey = data.readCString();
@@ -691,8 +715,23 @@ int32_t MediaAnalyticsItem::readFromParcel(const Parcel& data) {
 }
 
 int32_t MediaAnalyticsItem::writeToParcel(Parcel *data) {
+
     if (data == NULL) return -1;
 
+    int32_t version = 0;
+    data->writeInt32(version);
+
+    switch(version) {
+        case 0:
+          return writeToParcel0(data);
+          break;
+        default:
+          ALOGE("Unsupported MediaAnalyticsItem Parcel version: %d", version);
+          return -1;
+    }
+}
+
+int32_t MediaAnalyticsItem::writeToParcel0(Parcel *data) {
 
     data->writeCString(mKey.c_str());
     data->writeInt32(mPid);
@@ -737,7 +776,6 @@ int32_t MediaAnalyticsItem::writeToParcel(Parcel *data) {
     return 0;
 }
 
-
 const char *MediaAnalyticsItem::toCString() {
    return toCString(PROTO_LAST);
 }
@@ -876,8 +914,6 @@ bool MediaAnalyticsItem::selfrecord(bool forcenew) {
         }
         return true;
     } else {
-        std::string p = this->toString();
-        ALOGW("Unable to record: %s [forcenew=%d]", p.c_str(), forcenew);
         return false;
     }
 }
@@ -1035,5 +1071,170 @@ bool MediaAnalyticsItem::merge(MediaAnalyticsItem *incoming) {
     return true;
 }
 
+// a byte array; contents are
+// overall length (uint32) including the length field itself
+// encoding version (uint32)
+// count of properties (uint32)
+// N copies of:
+//     property name as length(int16), bytes
+//         the bytes WILL include the null terminator of the name
+//     type (uint8 -- 1 byte)
+//     size of value field (int16 -- 2 bytes)
+//     value (size based on type)
+//       int32, int64, double -- little endian 4/8/8 bytes respectively
+//       cstring -- N bytes of value [WITH terminator]
+
+enum { kInt32 = 0, kInt64, kDouble, kRate, kCString};
+
+bool MediaAnalyticsItem::dumpAttributes(char **pbuffer, size_t *plength) {
+
+    char *build = NULL;
+
+    if (pbuffer == NULL || plength == NULL)
+        return false;
+
+    // consistency for the caller, who owns whatever comes back in this pointer.
+    *pbuffer = NULL;
+
+    // first, let's calculate sizes
+    int32_t goal = 0;
+    int32_t version = 0;
+
+    goal += sizeof(uint32_t);   // overall length, including the length field
+    goal += sizeof(uint32_t);   // encoding version
+    goal += sizeof(uint32_t);   // # properties
+
+    int32_t count = mPropCount;
+    for (int i = 0 ; i < count; i++ ) {
+        Prop *prop = &mProps[i];
+        goal += sizeof(uint16_t);           // name length
+        goal += strlen(prop->mName) + 1;    // string + null
+        goal += sizeof(uint8_t);            // type
+        goal += sizeof(uint16_t);           // size of value
+        switch (prop->mType) {
+            case MediaAnalyticsItem::kTypeInt32:
+                    goal += sizeof(uint32_t);
+                    break;
+            case MediaAnalyticsItem::kTypeInt64:
+                    goal += sizeof(uint64_t);
+                    break;
+            case MediaAnalyticsItem::kTypeDouble:
+                    goal += sizeof(double);
+                    break;
+            case MediaAnalyticsItem::kTypeRate:
+                    goal += 2 * sizeof(uint64_t);
+                    break;
+            case MediaAnalyticsItem::kTypeCString:
+                    // length + actual string + null
+                    goal += strlen(prop->u.CStringValue) + 1;
+                    break;
+            default:
+                    ALOGE("found bad Prop type: %d, idx %d, name %s",
+                          prop->mType, i, prop->mName);
+                    return false;
+        }
+    }
+
+    // now that we have a size... let's allocate and fill
+    build = (char *)malloc(goal);
+    if (build == NULL)
+        return false;
+
+    memset(build, 0, goal);
+
+    char *filling = build;
+
+#define _INSERT(val, size) \
+    { memcpy(filling, &(val), (size)); filling += (size);}
+#define _INSERTSTRING(val, size) \
+    { memcpy(filling, (val), (size)); filling += (size);}
+
+    _INSERT(goal, sizeof(int32_t));
+    _INSERT(version, sizeof(int32_t));
+    _INSERT(count, sizeof(int32_t));
+
+    for (int i = 0 ; i < count; i++ ) {
+        Prop *prop = &mProps[i];
+        int16_t attrNameLen = strlen(prop->mName) + 1;
+        _INSERT(attrNameLen, sizeof(int16_t));
+        _INSERTSTRING(prop->mName, attrNameLen);    // termination included
+        int8_t elemtype;
+        int16_t elemsize;
+        switch (prop->mType) {
+            case MediaAnalyticsItem::kTypeInt32:
+                {
+                    elemtype = kInt32;
+                    _INSERT(elemtype, sizeof(int8_t));
+                    elemsize = sizeof(int32_t);
+                    _INSERT(elemsize, sizeof(int16_t));
+
+                    _INSERT(prop->u.int32Value, sizeof(int32_t));
+                    break;
+                }
+            case MediaAnalyticsItem::kTypeInt64:
+                {
+                    elemtype = kInt64;
+                    _INSERT(elemtype, sizeof(int8_t));
+                    elemsize = sizeof(int64_t);
+                    _INSERT(elemsize, sizeof(int16_t));
+
+                    _INSERT(prop->u.int64Value, sizeof(int64_t));
+                    break;
+                }
+            case MediaAnalyticsItem::kTypeDouble:
+                {
+                    elemtype = kDouble;
+                    _INSERT(elemtype, sizeof(int8_t));
+                    elemsize = sizeof(double);
+                    _INSERT(elemsize, sizeof(int16_t));
+
+                    _INSERT(prop->u.doubleValue, sizeof(double));
+                    break;
+                }
+            case MediaAnalyticsItem::kTypeRate:
+                {
+                    elemtype = kRate;
+                    _INSERT(elemtype, sizeof(int8_t));
+                    elemsize = 2 * sizeof(uint64_t);
+                    _INSERT(elemsize, sizeof(int16_t));
+
+                    _INSERT(prop->u.rate.count, sizeof(uint64_t));
+                    _INSERT(prop->u.rate.duration, sizeof(uint64_t));
+                    break;
+                }
+            case MediaAnalyticsItem::kTypeCString:
+                {
+                    elemtype = kCString;
+                    _INSERT(elemtype, sizeof(int8_t));
+                    elemsize = strlen(prop->u.CStringValue) + 1;
+                    _INSERT(elemsize, sizeof(int16_t));
+
+                    _INSERTSTRING(prop->u.CStringValue, elemsize);
+                    break;
+                }
+            default:
+                    // error if can't encode; warning if can't decode
+                    ALOGE("found bad Prop type: %d, idx %d, name %s",
+                          prop->mType, i, prop->mName);
+                    goto badness;
+        }
+    }
+
+    if (build + goal != filling) {
+        ALOGE("problems populating; wrote=%d planned=%d",
+              (int)(filling-build), goal);
+        goto badness;
+    }
+
+    *pbuffer = build;
+    *plength = goal;
+
+    return true;
+
+  badness:
+    free(build);
+    return false;
+}
+
 } // namespace android
 

media/libmediametrics/MediaMetrics.cpp

@@ -34,7 +34,7 @@
 
 // manage the overall record
 mediametrics_handle_t mediametrics_create(mediametricskey_t key) {
-    android::MediaAnalyticsItem *item = new android::MediaAnalyticsItem(key);
+    android::MediaAnalyticsItem *item = android::MediaAnalyticsItem::create(key);
     return (mediametrics_handle_t) item;
 }
 
@@ -187,18 +187,9 @@ bool mediametrics_isEnabled() {
     return android::MediaAnalyticsItem::isEnabled();
 }
 
-#if 0
-// do not expose this as is.
-// need to revisit (or redefine) how the android::Parcel parameter is handled
-// so that it meets the stable-API criteria for updateable components.
-//
-int32_t mediametrics_writeToParcel(mediametrics_handle_t handle, android::Parcel *parcel) {
+bool mediametrics_getAttributes(mediametrics_handle_t handle, char **buffer, size_t *length) {
     android::MediaAnalyticsItem *item = (android::MediaAnalyticsItem *) handle;
-    if (item == NULL) {
-        return -1;
-    }
-    return item->writeToParcel(parcel);
-}
-#endif
-
+    if (item == NULL) return false;
+    return item->dumpAttributes(buffer, length);
 
+}

media/libmediametrics/include/MediaAnalyticsItem.h

@@ -17,9 +17,10 @@
 #ifndef ANDROID_MEDIA_MEDIAANALYTICSITEM_H
 #define ANDROID_MEDIA_MEDIAANALYTICSITEM_H
 
-#include <cutils/properties.h>
 #include <string>
 #include <sys/types.h>
+
+#include <cutils/properties.h>
 #include <utils/Errors.h>
 #include <utils/KeyedVector.h>
 #include <utils/RefBase.h>
@@ -84,6 +85,10 @@ class MediaAnalyticsItem {
 
     public:
 
+        // so clients do not need to know size details
+        static MediaAnalyticsItem* create(Key key);
+        static MediaAnalyticsItem* create();
+
         // access functions for the class
         MediaAnalyticsItem();
         MediaAnalyticsItem(Key);
@@ -175,6 +180,9 @@ class MediaAnalyticsItem {
         int32_t writeToParcel(Parcel *);
         int32_t readFromParcel(const Parcel&);
 
+        // supports the stable interface
+        bool dumpAttributes(char **pbuffer, size_t *plength);
+
         std::string toString();
         std::string toString(int version);
         const char *toCString();
@@ -183,6 +191,11 @@ class MediaAnalyticsItem {
         // are we collecting analytics data
         static bool isEnabled();
 
+    private:
+        // handle Parcel version 0
+        int32_t writeToParcel0(Parcel *);
+        int32_t readFromParcel0(const Parcel&);
+
     protected:
 
         // merge fields from arg into this

media/libmediametrics/include/MediaMetrics.h

@@ -85,13 +85,9 @@ const char *mediametrics_readable(mediametrics_handle_t handle);
 void mediametrics_setUid(mediametrics_handle_t handle, uid_t uid);
 bool mediametrics_isEnabled();
 
-#if 0
-// do not expose this as is.
-// need to revisit (or redefine) how the android::Parcel parameter is handled
-// so that it meets the stable-API criteria for updateable components.
-//
-int32_t mediametrics_writeToParcel(mediametrics_handle_t handle, android::Parcel *parcel);
-#endif
+// serialized copy of the attributes/values, mostly for upstream getMetrics() calls
+// caller owns the buffer allocated as part of this call.
+bool mediametrics_getAttributes(mediametrics_handle_t handle, char **buffer, size_t *length);
 
 __END_DECLS
 

media/libmediametrics/libmediametrics.map.txt

@@ -0,0 +1,29 @@
+LIBMEDIAMETRICS_1 {
+  global:
+    mediametrics_addDouble; # apex
+    mediametrics_addInt32; # apex
+    mediametrics_addInt64; # apex
+    mediametrics_addRate; # apex
+    mediametrics_count; # apex
+    mediametrics_create; # apex
+    mediametrics_delete; # apex
+    mediametrics_freeCString; # apex
+    mediametrics_getAttributes; # apex
+    mediametrics_getCString; # apex
+    mediametrics_getDouble; # apex
+    mediametrics_getInt32; # apex
+    mediametrics_getInt64; # apex
+    mediametrics_getKey; # apex
+    mediametrics_getRate; # apex
+    mediametrics_isEnabled; # apex
+    mediametrics_readable; # apex
+    mediametrics_selfRecord; # apex
+    mediametrics_setCString; # apex
+    mediametrics_setDouble; # apex
+    mediametrics_setInt32; # apex
+    mediametrics_setInt64; # apex
+    mediametrics_setRate; # apex
+    mediametrics_setUid; # apex
+  local:
+    *;
+};