1 files changed, 38 insertions, 0 deletions
diff --git a/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/TimestampHelper.kt b/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/TimestampHelper.kt
new file mode 100644
index 0000000000..21069d7ce8
--- /dev/null
+++ b/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/TimestampHelper.kt
@@ -0,0 +1,38 @@
+public object FfiConverterTimestamp: FfiConverterRustBuffer<java.time.Instant> {
+    override fun read(buf: ByteBuffer): java.time.Instant {
+        val seconds = buf.getLong()
+        // Type mismatch (should be u32) but we check for overflow/underflow below
+        val nanoseconds = buf.getInt().toLong()
+        if (nanoseconds < 0) {
+            throw java.time.DateTimeException("Instant nanoseconds exceed minimum or maximum supported by uniffi")
+        }
+        if (seconds >= 0) {
+            return java.time.Instant.EPOCH.plus(java.time.Duration.ofSeconds(seconds, nanoseconds))
+        } else {
+            return java.time.Instant.EPOCH.minus(java.time.Duration.ofSeconds(-seconds, nanoseconds))
+        }
+    }
+
+    // 8 bytes for seconds, 4 bytes for nanoseconds
+    override fun allocationSize(value: java.time.Instant) = 12
+
+    override fun write(value: java.time.Instant, buf: ByteBuffer) {
+        var epochOffset = java.time.Duration.between(java.time.Instant.EPOCH, value)
+
+        var sign = 1
+        if (epochOffset.isNegative()) {
+            sign = -1
+            epochOffset = epochOffset.negated()
+        }
+
+        if (epochOffset.nano < 0) {
+            // Java docs provide guarantee that nano will always be positive, so this should be impossible
+            // See: https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html
+            throw IllegalArgumentException("Invalid timestamp, nano value must be non-negative")
+        }
+
+        buf.putLong(sign * epochOffset.seconds)
+        // Type mismatch (should be u32) but since values will always be between 0 and 999,999,999 it should be OK
+        buf.putInt(epochOffset.nano)
+    }
+}