Simplify header and message creation, add closeable

Centralize header and message creation around building up modifiable
headers/messages and then copying them to make them unmodifiable. This
centralizes all formatting and grouping and trimming logic for headers,
and we have some "fast-paths" for making copies since we know headers
were already formatted and grouped.

This also updates HttpMessage to be closeable so it cleans up any
contained DataStream.

Author: mtdowling

aws/aws-sigv4/src/main/java/software/amazon/smithy/java/aws/client/auth/scheme/sigv4/SigV4Signer.java

@@ -41,6 +41,7 @@ final class SigV4Signer implements Signer<HttpRequest, AwsCredentialsIdentity> {
     private static final InternalLogger LOGGER = InternalLogger.getLogger(SigV4Signer.class);
     private static final List<String> HEADERS_TO_IGNORE_IN_LOWER_CASE = List.of(
             "connection",
+            "content-length",
             "x-amzn-trace-id",
             "user-agent",
             "expect");

client/client-http/src/main/java/software/amazon/smithy/java/client/http/JavaHttpClientTransport.java

@@ -134,8 +134,11 @@ private java.net.http.HttpRequest createJavaRequest(Context context, HttpRequest
 
         // Any explicitly set headers overwrite existing headers, they do not merge.
         for (var entry : request.headers().map().entrySet()) {
-            for (var value : entry.getValue()) {
-                httpRequestBuilder.setHeader(entry.getKey(), value);
+            // Skip restricted headers
+            if (!entry.getKey().equals("content-length")) {
+                for (var value : entry.getValue()) {
+                    httpRequestBuilder.setHeader(entry.getKey(), value);
+                }
             }
         }
 

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpHeaders.java

@@ -110,7 +110,18 @@ default boolean isEmpty() {
      *
      * @return the created modifiable headers.
      */
-    ModifiableHttpHeaders toModifiable();
+    default ModifiableHttpHeaders toModifiable() {
+        return SimpleModifiableHttpHeaders.of(this);
+    }
+
+    /**
+     * Get an unmodifiable version of the headers.
+     *
+     * @return the unmodifiable headers.
+     */
+    default HttpHeaders toUnmodifiable() {
+        return SimpleUnmodifiableHttpHeaders.of(this);
+    }
 
     /**
      * Normalizes an HTTP header name by trimming whitespace and converting ASCII uppercase to lowercase.

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpMessage.java

@@ -13,8 +13,10 @@
 
 /**
  * HTTP message.
+ *
+ * <p>When closed, the body of the message is also closed.
  */
-public interface HttpMessage {
+public interface HttpMessage extends AutoCloseable {
     /**
      * Get the HTTP version.
      *
@@ -70,12 +72,20 @@ default long contentLength(long defaultValue) {
     HttpHeaders headers();
 
     /**
-     * Get the body of the message, or null.
+     * Get the body of the message.
      *
-     * @return the message body or null.
+     * @return the message body (never null, may be zero length).
      */
     DataStream body();
 
+    @Override
+    default void close() {
+        var body = body();
+        if (body != null) {
+            body.close();
+        }
+    }
+
     /**
      * Builder for HTTP messages.
      *

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpRequest.java

@@ -32,6 +32,13 @@ public interface HttpRequest extends HttpMessage {
      */
     ModifiableHttpRequest toModifiable();
 
+    /**
+     * Creates an unmodifiable copy of the request, or returns it as is if it is already unmodifiable.
+     *
+     * @return the unmodifiable version of this request.
+     */
+    HttpRequest toUnmodifiable();
+
     /**
      * Create a builder configured with the values of the request.
      *

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpRequestImpl.java

@@ -20,6 +20,15 @@ record HttpRequestImpl(
         HttpHeaders headers,
         DataStream body) implements HttpRequest {
 
+    HttpRequestImpl(ModifiableHttpRequestImpl from) {
+        this(from.httpVersion(), from.method(), from.uri(), from.headers().toUnmodifiable(), from.body());
+    }
+
+    @Override
+    public HttpRequest toUnmodifiable() {
+        return this;
+    }
+
     @Override
     public ModifiableHttpRequest toModifiable() {
         var mod = new ModifiableHttpRequestImpl();
@@ -32,28 +41,22 @@ public ModifiableHttpRequest toModifiable() {
     }
 
     static final class Builder implements HttpRequest.Builder {
-
-        String method;
-        URI uri;
-        DataStream body;
-        HttpHeaders headers = SimpleUnmodifiableHttpHeaders.EMPTY;
-        HttpVersion httpVersion = HttpVersion.HTTP_1_1;
-        private Map<String, List<String>> mutatedHeaders;
+        private final ModifiableHttpRequest modifiableHttpRequest = new ModifiableHttpRequestImpl();
 
         Builder() {}
 
         public Builder httpVersion(HttpVersion httpVersion) {
-            this.httpVersion = httpVersion;
+            modifiableHttpRequest.setHttpVersion(httpVersion);
             return this;
         }
 
         public Builder method(String method) {
-            this.method = method;
+            modifiableHttpRequest.setMethod(method);
             return this;
         }
 
         public Builder uri(URI uri) {
-            this.uri = uri;
+            modifiableHttpRequest.setUri(uri);
             return this;
         }
 
@@ -62,61 +65,49 @@ public Builder body(Flow.Publisher<ByteBuffer> publisher) {
         }
 
         public Builder body(DataStream body) {
-            this.body = body;
+            modifiableHttpRequest.setBody(body);
             return this;
         }
 
-        public Builder headers(HttpHeaders headers) {
-            this.headers = Objects.requireNonNull(headers);
-            mutatedHeaders = null;
+        @Override
+        public HttpRequest.Builder headers(HttpHeaders headers) {
+            modifiableHttpRequest.setHeaders(headers.toModifiable());
             return this;
         }
 
         @Override
         public Builder withAddedHeader(String name, String value) {
-            mutatedHeaders = SimpleUnmodifiableHttpHeaders.addHeader(this.headers, mutatedHeaders, name, value);
+            modifiableHttpRequest.headers().addHeader(name, value);
             return this;
         }
 
         @Override
         public Builder withAddedHeaders(Map<String, List<String>> headers) {
-            mutatedHeaders = SimpleUnmodifiableHttpHeaders.addHeaders(this.headers, mutatedHeaders, headers);
+            modifiableHttpRequest.headers().addHeaders(headers);
             return this;
         }
 
         @Override
         public Builder withReplacedHeaders(Map<String, List<String>> headers) {
-            mutatedHeaders = SimpleUnmodifiableHttpHeaders.replaceHeaders(this.headers, mutatedHeaders, headers);
+            modifiableHttpRequest.headers().setHeaders(headers);
             return this;
         }
 
         private void beforeBuild() {
-            if (mutatedHeaders != null) {
-                headers = new SimpleUnmodifiableHttpHeaders(mutatedHeaders, false);
-            }
-            Objects.requireNonNull(httpVersion, "HttpVersion cannot be null");
-            Objects.requireNonNull(method, "Method cannot be null");
-            Objects.requireNonNull(uri, "URI cannot be null");
-            body = Objects.requireNonNullElse(body, DataStream.ofEmpty());
-            mutatedHeaders = null; // decouple from built request
+            Objects.requireNonNull(modifiableHttpRequest.method(), "method not set");
+            Objects.requireNonNull(modifiableHttpRequest.uri(), "uri not set");
         }
 
         @Override
         public HttpRequest build() {
             beforeBuild();
-            return new HttpRequestImpl(httpVersion, method, uri, headers, body);
+            return modifiableHttpRequest.toUnmodifiable();
         }
 
         @Override
         public ModifiableHttpRequest buildModifiable() {
             beforeBuild();
-            var mod = new ModifiableHttpRequestImpl();
-            mod.setHttpVersion(httpVersion);
-            mod.setMethod(method);
-            mod.setUri(uri);
-            mod.setHeaders(headers.toModifiable());
-            mod.setBody(body);
-            return mod;
+            return modifiableHttpRequest.copy();
         }
     }
 }

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpResponse.java

@@ -23,6 +23,13 @@ public interface HttpResponse extends HttpMessage {
      */
     ModifiableHttpResponse toModifiable();
 
+    /**
+     * Creates an unmodifiable copy of the request, or returns it as is if it is already unmodifiable.
+     *
+     * @return the unmodifiable version of this request.
+     */
+    HttpResponse toUnmodifiable();
+
     /**
      * Create a builder configured with the values of the response.
      *

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpResponseImpl.java

@@ -7,7 +7,6 @@
 
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import software.amazon.smithy.java.io.datastream.DataStream;
 
 record HttpResponseImpl(
@@ -16,6 +15,15 @@ record HttpResponseImpl(
         HttpHeaders headers,
         DataStream body) implements HttpResponse {
 
+    HttpResponseImpl(ModifiableHttpResponse from) {
+        this(from.httpVersion(), from.statusCode(), from.headers().toUnmodifiable(), from.body());
+    }
+
+    @Override
+    public HttpResponse toUnmodifiable() {
+        return this;
+    }
+
     @Override
     public ModifiableHttpResponse toModifiable() {
         var mod = new ModifiableHttpResponseImpl();
@@ -27,84 +35,60 @@ public ModifiableHttpResponse toModifiable() {
     }
 
     static final class Builder implements HttpResponse.Builder {
-        int statusCode;
-        DataStream body;
-        HttpHeaders headers = SimpleUnmodifiableHttpHeaders.EMPTY;
-        HttpVersion httpVersion = HttpVersion.HTTP_1_1;
-        private Map<String, List<String>> mutatedHeaders;
+        ModifiableHttpResponseImpl modifiableResponse = new ModifiableHttpResponseImpl();
 
         Builder() {}
 
         @Override
         public Builder httpVersion(HttpVersion httpVersion) {
-            this.httpVersion = httpVersion;
+            modifiableResponse.setHttpVersion(httpVersion);
             return this;
         }
 
         @Override
         public Builder statusCode(int statusCode) {
-            this.statusCode = statusCode;
+            modifiableResponse.setStatusCode(statusCode);
             return this;
         }
 
         @Override
         public Builder body(DataStream body) {
-            this.body = body;
+            modifiableResponse.setBody(body);
             return this;
         }
 
         @Override
         public Builder headers(HttpHeaders headers) {
-            this.headers = Objects.requireNonNull(headers);
-            mutatedHeaders = null;
+            modifiableResponse.setHeaders(headers.toModifiable());
             return this;
         }
 
         @Override
         public Builder withAddedHeader(String name, String value) {
-            mutatedHeaders = SimpleUnmodifiableHttpHeaders.addHeader(this.headers, mutatedHeaders, name, value);
+            modifiableResponse.headers().addHeader(name, value);
             return this;
         }
 
         @Override
         public Builder withAddedHeaders(Map<String, List<String>> headers) {
-            mutatedHeaders = SimpleUnmodifiableHttpHeaders.addHeaders(this.headers, mutatedHeaders, headers);
+            modifiableResponse.headers().addHeaders(headers);
             return this;
         }
 
         @Override
         public Builder withReplacedHeaders(Map<String, List<String>> headers) {
-            mutatedHeaders = SimpleUnmodifiableHttpHeaders.replaceHeaders(this.headers, mutatedHeaders, headers);
+            modifiableResponse.headers().setHeaders(headers);
             return this;
         }
 
-        private void beforeBuild() {
-            if (statusCode == 0) {
-                throw new IllegalStateException("No status code was set on response");
-            }
-            if (mutatedHeaders != null) {
-                headers = new SimpleUnmodifiableHttpHeaders(mutatedHeaders, false);
-            }
-            Objects.requireNonNull(httpVersion);
-            body = Objects.requireNonNullElse(body, DataStream.ofEmpty());
-            mutatedHeaders = null; // decouple from built response
-        }
-
         @Override
         public HttpResponse build() {
-            beforeBuild();
-            return new HttpResponseImpl(httpVersion, statusCode, headers, body);
+            return modifiableResponse.toUnmodifiable();
         }
 
         @Override
         public ModifiableHttpResponse buildModifiable() {
-            beforeBuild();
-            var mod = new ModifiableHttpResponseImpl();
-            mod.setHttpVersion(httpVersion);
-            mod.setStatusCode(statusCode);
-            mod.setHeaders(headers.toModifiable());
-            mod.setBody(body);
-            return mod;
+            return modifiableResponse.copy();
         }
     }
 }

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpVersion.java

@@ -9,6 +9,7 @@
  * Enumeration of the HTTP protocol versions.
  */
 public enum HttpVersion {
+    HTTP_1_0,
     HTTP_1_1,
     HTTP_2;
 
@@ -20,15 +21,17 @@ public enum HttpVersion {
      */
     public static HttpVersion from(String version) {
         return switch (version) {
-            case "HTTP/1.1" -> HTTP_1_1;
-            case "HTTP/2.0" -> HTTP_2;
+            case "HTTP/1.0", "http/1.0" -> HTTP_1_0;
+            case "HTTP/1.1", "http/1.1" -> HTTP_1_1;
+            case "HTTP/2.0", "h2" -> HTTP_2;
             default -> throw new UnsupportedOperationException("Unsupported HTTP version: " + version);
         };
     }
 
     @Override
     public String toString() {
         return switch (this) {
+            case HTTP_1_0 -> "HTTP/1.0";
             case HTTP_1_1 -> "HTTP/1.1";
             case HTTP_2 -> "HTTP/2.0";
         };