1 files changed, 24 insertions, 15 deletions
diff --git a/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/RustBufferTemplate.kt b/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/RustBufferTemplate.kt
index dfbea24074..b28f25bfc3 100644
--- a/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/RustBufferTemplate.kt
+++ b/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/RustBufferTemplate.kt
@@ -4,32 +4,41 @@
 
 @Structure.FieldOrder("capacity", "len", "data")
 open class RustBuffer : Structure() {
-    @JvmField var capacity: Int = 0
-    @JvmField var len: Int = 0
+    // Note: `capacity` and `len` are actually `ULong` values, but JVM only supports signed values.
+    // When dealing with these fields, make sure to call `toULong()`.
+    @JvmField var capacity: Long = 0
+    @JvmField var len: Long = 0
     @JvmField var data: Pointer? = null
 
     class ByValue: RustBuffer(), Structure.ByValue
     class ByReference: RustBuffer(), Structure.ByReference
 
+   internal fun setValue(other: RustBuffer) {
+        capacity = other.capacity
+        len = other.len
+        data = other.data
+    }
+
     companion object {
-        internal fun alloc(size: Int = 0) = rustCall() { status ->
-            _UniFFILib.INSTANCE.{{ ci.ffi_rustbuffer_alloc().name() }}(size, status)
+        internal fun alloc(size: ULong = 0UL) = uniffiRustCall() { status ->
+            // Note: need to convert the size to a `Long` value to make this work with JVM.
+            UniffiLib.INSTANCE.{{ ci.ffi_rustbuffer_alloc().name() }}(size.toLong(), status)
         }.also {
             if(it.data == null) {
                throw RuntimeException("RustBuffer.alloc() returned null data pointer (size=${size})")
            }
         }
 
-        internal fun create(capacity: Int, len: Int, data: Pointer?): RustBuffer.ByValue {
+        internal fun create(capacity: ULong, len: ULong, data: Pointer?): RustBuffer.ByValue {
             var buf = RustBuffer.ByValue()
-            buf.capacity = capacity
-            buf.len = len
+            buf.capacity = capacity.toLong()
+            buf.len = len.toLong()
             buf.data = data
             return buf
         }
 
-        internal fun free(buf: RustBuffer.ByValue) = rustCall() { status ->
-            _UniFFILib.INSTANCE.{{ ci.ffi_rustbuffer_free().name() }}(buf, status)
+        internal fun free(buf: RustBuffer.ByValue) = uniffiRustCall() { status ->
+            UniffiLib.INSTANCE.{{ ci.ffi_rustbuffer_free().name() }}(buf, status)
         }
     }
 
@@ -53,9 +62,9 @@ class RustBufferByReference : ByReference(16) {
     fun setValue(value: RustBuffer.ByValue) {
         // NOTE: The offsets are as they are in the C-like struct.
         val pointer = getPointer()
-        pointer.setInt(0, value.capacity)
-        pointer.setInt(4, value.len)
-        pointer.setPointer(8, value.data)
+        pointer.setLong(0, value.capacity)
+        pointer.setLong(8, value.len)
+        pointer.setPointer(16, value.data)
     }
 
     /**
@@ -64,9 +73,9 @@ class RustBufferByReference : ByReference(16) {
     fun getValue(): RustBuffer.ByValue {
         val pointer = getPointer()
         val value = RustBuffer.ByValue()
-        value.writeField("capacity", pointer.getInt(0))
-        value.writeField("len", pointer.getInt(4))
-        value.writeField("data", pointer.getPointer(8))
+        value.writeField("capacity", pointer.getLong(0))
+        value.writeField("len", pointer.getLong(8))
+        value.writeField("data", pointer.getLong(16))
 
         return value
     }