commit 07fb9c90f688db3b2ac5128fe0020cc4d5b06d32
author Steven Moreland <smoreland@google.com> Thu Nov 01 17:14:29 2018 -0700
committer Steven Moreland <smoreland@google.com> Mon Nov 05 15:19:17 2018 -0800
tree b33cee275a96e11e28ad3860e190f97b9f07fb05
parent 9ac9dcae8daf990448515b69663a2a534814bbf1

libbinder_ndk: read/write string array

Bug: 111445392
Test: atest android.binder.cts
Change-Id: I75fd01d8e1c170aac2063b5c466767e111e5787a

libs/binder/ndk/parcel.cpp

diff --git a/libs/binder/ndk/parcel.cpp b/libs/binder/ndk/parcel.cpp
index d9f469ba..3b44a62 100644
--- a/libs/binder/ndk/parcel.cpp
+++ b/libs/binder/ndk/parcel.cpp
@@ -273,8 +273,8 @@
     return STATUS_OK;
 }
 
-binder_status_t AParcel_readString(const AParcel* parcel, AParcel_stringAllocator allocator,
-                                   void* stringData) {
+binder_status_t AParcel_readString(const AParcel* parcel, void* stringData,
+                                   AParcel_stringAllocator allocator) {
     size_t len16;
     const char16_t* str16 = parcel->get()->readString16Inplace(&len16);
 
@@ -291,7 +291,7 @@
         len8 = utf16_to_utf8_length(str16, len16) + 1;
     }
 
-    if (len8 <= 0 || len8 >= std::numeric_limits<int32_t>::max()) {
+    if (len8 <= 0 || len8 > std::numeric_limits<int32_t>::max()) {
         LOG(WARNING) << __func__ << ": Invalid string length: " << len8;
         return STATUS_BAD_VALUE;
     }
@@ -308,6 +308,68 @@
     return STATUS_OK;
 }
 
+binder_status_t AParcel_writeStringArray(AParcel* parcel, const void* arrayData, size_t length,
+                                         AParcel_stringArrayElementGetter getter) {
+    if (length > std::numeric_limits<int32_t>::max()) return STATUS_BAD_VALUE;
+
+    Parcel* rawParcel = parcel->get();
+
+    status_t status = rawParcel->writeInt32(static_cast<int32_t>(length));
+    if (status != STATUS_OK) return PruneStatusT(status);
+
+    for (size_t i = 0; i < length; i++) {
+        size_t length = 0;
+        const char* str = getter(arrayData, i, &length);
+        if (str == nullptr) return STATUS_BAD_VALUE;
+
+        binder_status_t status = AParcel_writeString(parcel, str, length);
+        if (status != STATUS_OK) return status;
+    }
+
+    return STATUS_OK;
+}
+
+// This implements AParcel_stringAllocator for a string using an array, index, and element
+// allocator.
+struct StringArrayElementAllocationAdapter {
+    void* arrayData; // stringData from the NDK
+    size_t index;    // index into the string array
+    AParcel_stringArrayElementAllocator elementAllocator;
+
+    static char* Allocator(void* stringData, size_t length) {
+        StringArrayElementAllocationAdapter* adapter =
+                static_cast<StringArrayElementAllocationAdapter*>(stringData);
+        return adapter->elementAllocator(adapter->arrayData, adapter->index, length);
+    }
+};
+
+binder_status_t AParcel_readStringArray(const AParcel* parcel, void* arrayData,
+                                        AParcel_stringArrayAllocator allocator,
+                                        AParcel_stringArrayElementAllocator elementAllocator) {
+    const Parcel* rawParcel = parcel->get();
+
+    int32_t length;
+    status_t status = rawParcel->readInt32(&length);
+
+    if (status != STATUS_OK) return PruneStatusT(status);
+    if (length < 0) return STATUS_UNEXPECTED_NULL;
+
+    if (!allocator(arrayData, length)) return STATUS_NO_MEMORY;
+
+    StringArrayElementAllocationAdapter adapter{
+            .arrayData = arrayData,
+            .index = 0,
+            .elementAllocator = elementAllocator,
+    };
+
+    for (; adapter.index < length; adapter.index++) {
+        AParcel_readString(parcel, static_cast<void*>(&adapter),
+                           StringArrayElementAllocationAdapter::Allocator);
+    }
+
+    return STATUS_OK;
+}
+
 // See gen_parcel_helper.py. These auto-generated read/write methods use the same types for
 // libbinder and this library.
 // @START