feat: Add types to support continuous sessions with a sliding window

PiperOrigin-RevId: 745348707

Author: Annhiluc

src/main/java/com/google/genai/types/ContextWindowCompressionConfig.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Auto-generated code. Do not edit.
+
+package com.google.genai.types;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.google.auto.value.AutoValue;
+import com.google.genai.JsonSerializable;
+import java.util.Optional;
+
+/**
+ * Enables context window compression -- mechanism managing model context window so it does not
+ * exceed given length.
+ */
+@AutoValue
+@JsonDeserialize(builder = ContextWindowCompressionConfig.Builder.class)
+public abstract class ContextWindowCompressionConfig extends JsonSerializable {
+  /** Number of tokens (before running turn) that triggers context window compression mechanism. */
+  @JsonProperty("triggerTokens")
+  public abstract Optional<Long> triggerTokens();
+
+  /** Sliding window compression mechanism. */
+  @JsonProperty("slidingWindow")
+  public abstract Optional<SlidingWindow> slidingWindow();
+
+  /** Instantiates a builder for ContextWindowCompressionConfig. */
+  public static Builder builder() {
+    return new AutoValue_ContextWindowCompressionConfig.Builder();
+  }
+
+  /** Creates a builder with the same values as this instance. */
+  public abstract Builder toBuilder();
+
+  /** Builder for ContextWindowCompressionConfig. */
+  @AutoValue.Builder
+  public abstract static class Builder {
+    /**
+     * For internal usage. Please use `ContextWindowCompressionConfig.builder()` for instantiation.
+     */
+    @JsonCreator
+    private static Builder create() {
+      return new AutoValue_ContextWindowCompressionConfig.Builder();
+    }
+
+    @JsonProperty("triggerTokens")
+    public abstract Builder triggerTokens(Long triggerTokens);
+
+    @JsonProperty("slidingWindow")
+    public abstract Builder slidingWindow(SlidingWindow slidingWindow);
+
+    public abstract ContextWindowCompressionConfig build();
+  }
+
+  /** Deserializes a JSON string to a ContextWindowCompressionConfig object. */
+  public static ContextWindowCompressionConfig fromJson(String jsonString) {
+    return JsonSerializable.fromJsonString(jsonString, ContextWindowCompressionConfig.class);
+  }
+}

src/main/java/com/google/genai/types/SlidingWindow.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Auto-generated code. Do not edit.
+
+package com.google.genai.types;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.google.auto.value.AutoValue;
+import com.google.genai.JsonSerializable;
+import java.util.Optional;
+
+/**
+ * Context window will be truncated by keeping only suffix of it.
+ *
+ * <p>Context window will always be cut at start of USER role turn. System instructions and
+ * `BidiGenerateContentSetup.prefix_turns` will not be subject to the sliding window mechanism, they
+ * will always stay at the beginning of context window.
+ */
+@AutoValue
+@JsonDeserialize(builder = SlidingWindow.Builder.class)
+public abstract class SlidingWindow extends JsonSerializable {
+  /**
+   * Session reduction target -- how many tokens we should keep. Window shortening operation has
+   * some latency costs, so we should avoid running it on every turn. Should be < trigger_tokens. If
+   * not set, trigger_tokens/2 is assumed.
+   */
+  @JsonProperty("targetTokens")
+  public abstract Optional<Long> targetTokens();
+
+  /** Instantiates a builder for SlidingWindow. */
+  public static Builder builder() {
+    return new AutoValue_SlidingWindow.Builder();
+  }
+
+  /** Creates a builder with the same values as this instance. */
+  public abstract Builder toBuilder();
+
+  /** Builder for SlidingWindow. */
+  @AutoValue.Builder
+  public abstract static class Builder {
+    /** For internal usage. Please use `SlidingWindow.builder()` for instantiation. */
+    @JsonCreator
+    private static Builder create() {
+      return new AutoValue_SlidingWindow.Builder();
+    }
+
+    @JsonProperty("targetTokens")
+    public abstract Builder targetTokens(Long targetTokens);
+
+    public abstract SlidingWindow build();
+  }
+
+  /** Deserializes a JSON string to a SlidingWindow object. */
+  public static SlidingWindow fromJson(String jsonString) {
+    return JsonSerializable.fromJsonString(jsonString, SlidingWindow.class);
+  }
+}