From 31c1beb1d8de373f7734a54e25ad80b01024adb0 Mon Sep 17 00:00:00 2001
From: Christopher Wiley <wiley@google.com>
Date: Fri, 19 Aug 2016 11:43:54 -0700
Subject: libbinder: Support reading/writing out T[] lengths

T[] types are special: the length of the out array is written
into the inbound parcel to signal the expected length to the
server.

Bug: 30836680
Change-Id: I4f2f39fd7b1a6b94a25bd7f6c3baed430fd567bc
Test: integration tests pass with this change.
---
 include/binder/Parcel.h | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/include/binder/Parcel.h b/include/binder/Parcel.h
index fe3aed6213..7ee25dd19f 100644
--- a/include/binder/Parcel.h
+++ b/include/binder/Parcel.h
@@ -166,6 +166,10 @@ public:
     template<typename T>
     status_t            write(const LightFlattenable<T>& val);
 
+    template<typename T>
+    status_t            writeVectorSize(const std::vector<T>& val);
+    template<typename T>
+    status_t            writeVectorSize(const std::unique_ptr<std::vector<T>>& val);
 
     // Place a native_handle into the parcel (the native_handle's file-
     // descriptors are dup'ed, so it is safe to delete the native_handle
@@ -305,6 +309,11 @@ public:
     template<typename T>
     status_t            read(LightFlattenable<T>& val) const;
 
+    template<typename T>
+    status_t            resizeOutVector(std::vector<T>* val) const;
+    template<typename T>
+    status_t            resizeOutVector(std::unique_ptr<std::vector<T>>* val) const;
+
     // Like Parcel.java's readExceptionCode().  Reads the first int32
     // off of a Parcel's header, returning 0 or the negative error
     // code on exceptions, but also deals with skipping over rich
@@ -563,6 +572,54 @@ status_t Parcel::read(LightFlattenable<T>& val) const {
     return NO_ERROR;
 }
 
+template<typename T>
+status_t Parcel::writeVectorSize(const std::vector<T>& val) {
+    if (val.size() > INT32_MAX) {
+        return BAD_VALUE;
+    }
+    return writeInt32(val.size());
+}
+
+template<typename T>
+status_t Parcel::writeVectorSize(const std::unique_ptr<std::vector<T>>& val) {
+    if (!val) {
+        return writeInt32(-1);
+    }
+
+    return writeVectorSize(*val);
+}
+
+template<typename T>
+status_t Parcel::resizeOutVector(std::vector<T>* val) const {
+    int32_t size;
+    status_t err = readInt32(&size);
+    if (err != NO_ERROR) {
+        return err;
+    }
+
+    if (size < 0) {
+        return UNEXPECTED_NULL;
+    }
+    val->resize(size_t(size));
+    return OK;
+}
+
+template<typename T>
+status_t Parcel::resizeOutVector(std::unique_ptr<std::vector<T>>* val) const {
+    int32_t size;
+    status_t err = readInt32(&size);
+    if (err != NO_ERROR) {
+        return err;
+    }
+
+    val->reset();
+    if (size >= 0) {
+        val->reset(new std::vector<T>(size_t(size)));
+    }
+
+    return OK;
+}
+
 template<typename T>
 status_t Parcel::readStrongBinder(sp<T>* val) const {
     sp<IBinder> tmp;
-- 
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