1 // Copyright 2024 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/android/jni_bytebuffer.h"
6
7 #include "base/numerics/safe_conversions.h"
8
9 namespace base::android {
10
JavaByteBufferToSpan(JNIEnv * env,jobject buffer)11 base::span<const uint8_t> JavaByteBufferToSpan(JNIEnv* env, jobject buffer) {
12 auto span = MaybeJavaByteBufferToSpan(env, buffer);
13 CHECK(span.has_value());
14 return *span;
15 }
16
JavaByteBufferToMutableSpan(JNIEnv * env,jobject buffer)17 base::span<uint8_t> JavaByteBufferToMutableSpan(JNIEnv* env, jobject buffer) {
18 auto span = MaybeJavaByteBufferToMutableSpan(env, buffer);
19 CHECK(span.has_value());
20 return *span;
21 }
22
MaybeJavaByteBufferToSpan(JNIEnv * env,jobject buffer)23 std::optional<base::span<const uint8_t>> MaybeJavaByteBufferToSpan(
24 JNIEnv* env,
25 jobject buffer) {
26 auto span = MaybeJavaByteBufferToMutableSpan(env, buffer);
27 return span ? std::make_optional(base::span<const uint8_t>(*span))
28 : std::nullopt;
29 }
30
MaybeJavaByteBufferToMutableSpan(JNIEnv * env,jobject buffer)31 std::optional<base::span<uint8_t>> MaybeJavaByteBufferToMutableSpan(
32 JNIEnv* env,
33 jobject buffer) {
34 void* data = env->GetDirectBufferAddress(buffer);
35 jlong size = env->GetDirectBufferCapacity(buffer);
36
37 // !data && size == 0 is allowed - this is how a 0-length Buffer is
38 // represented.
39 if (size < 0 || (!data && size > 0)) {
40 return std::nullopt;
41 }
42
43 return base::span<uint8_t>(static_cast<uint8_t*>(data),
44 base::checked_cast<size_t>(size));
45 }
46
47 } // namespace base::android
48