From 17c5a4420f5d2acc2e733bd5efa693b16436e9bf Mon Sep 17 00:00:00 2001
From: Mikhail Arzhaev <marzhaev@texenergo.com>
Date: Tue, 16 Mar 2021 20:17:01 +0300
Subject: [PATCH 1/2] Move head_object_output to the dedicated folder. Add
 frequently used etag and meta accessors.

---
 src/awscr-s3/client.cr                             |  2 ++
 src/awscr-s3/{ => responses}/head_object_output.cr | 14 ++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)
 rename src/awscr-s3/{ => responses}/head_object_output.cr (69%)

diff --git a/src/awscr-s3/client.cr b/src/awscr-s3/client.cr
index f2bdd69..b790bd8 100644
--- a/src/awscr-s3/client.cr
+++ b/src/awscr-s3/client.cr
@@ -268,6 +268,8 @@ module Awscr::S3
     # p resp.size          # => 123
     # p resp.status        # => HTTP::Status::OK
     # p resp.last_modified # => "Wed, 19 Jun 2019 11:55:33 GMT"
+    # p resp.etag          # => ""
+    # p resp.meta          # => {"my_tag" => "my_value"}
     # ```
     def head_object(bucket, object : String, headers : Hash(String, String) = Hash(String, String).new)
       resp = http.head("/#{bucket}/#{Util.encode(object)}", headers: headers)
diff --git a/src/awscr-s3/head_object_output.cr b/src/awscr-s3/responses/head_object_output.cr
similarity index 69%
rename from src/awscr-s3/head_object_output.cr
rename to src/awscr-s3/responses/head_object_output.cr
index 99b02c4..b7e34ed 100644
--- a/src/awscr-s3/head_object_output.cr
+++ b/src/awscr-s3/responses/head_object_output.cr
@@ -9,10 +9,18 @@ module Awscr::S3::Response
     getter content_type : String
     getter last_modified : Time
     getter size : UInt64
+    getter etag : String
+    getter meta : Hash(String, String)
 
     # Create a `GetObjectOutput` response from an
     # `HTTP::Client::Response` object
-    def self.from_response(response)
+    def self.from_response(response : HTTP::Client::Response)
+      meta = {} of String => String
+      response.headers.each do |k, v|
+        next unless k.starts_with?("x-amz-meta-")
+        meta[k.lchop("x-amz-meta-")] = v.first
+      end
+
       new(
         status: response.status,
         status_message: response.status_message,
@@ -20,10 +28,12 @@ module Awscr::S3::Response
         content_type: response.headers["Content-Type"],
         last_modified: self.parse_date(response.headers["Last-Modified"]),
         size: response.headers["Content-Length"].to_u64,
+        etag: response.headers["ETag"].strip('"'),
+        meta: meta
       )
     end
 
-    def initialize(@status, @status_message, @headers, @content_type, @last_modified, @size)
+    def initialize(@status, @status_message, @headers, @content_type, @last_modified, @size, @etag, @meta)
     end
 
     private def self.parse_date(date : String)

From 8c5aabc15eff05f1861d6fe450e09b4b1a043ec6 Mon Sep 17 00:00:00 2001
From: Mikhail Arzhaev <marzhaev@texenergo.com>
Date: Tue, 16 Mar 2021 20:33:41 +0300
Subject: [PATCH 2/2] Move frequently accessed response data from class init to
 class's instance methods.

---
 src/awscr-s3/responses/head_object_output.cr | 49 ++++++++++++--------
 1 file changed, 30 insertions(+), 19 deletions(-)

diff --git a/src/awscr-s3/responses/head_object_output.cr b/src/awscr-s3/responses/head_object_output.cr
index b7e34ed..204b55e 100644
--- a/src/awscr-s3/responses/head_object_output.cr
+++ b/src/awscr-s3/responses/head_object_output.cr
@@ -6,37 +6,48 @@ module Awscr::S3::Response
     getter status : HTTP::Status
     getter status_message : String | Nil
     getter headers : HTTP::Headers
-    getter content_type : String
-    getter last_modified : Time
-    getter size : UInt64
-    getter etag : String
-    getter meta : Hash(String, String)
 
     # Create a `GetObjectOutput` response from an
     # `HTTP::Client::Response` object
     def self.from_response(response : HTTP::Client::Response)
-      meta = {} of String => String
-      response.headers.each do |k, v|
-        next unless k.starts_with?("x-amz-meta-")
-        meta[k.lchop("x-amz-meta-")] = v.first
-      end
-
       new(
         status: response.status,
         status_message: response.status_message,
-        headers: response.headers,
-        content_type: response.headers["Content-Type"],
-        last_modified: self.parse_date(response.headers["Last-Modified"]),
-        size: response.headers["Content-Length"].to_u64,
-        etag: response.headers["ETag"].strip('"'),
-        meta: meta
+        headers: response.headers
       )
     end
 
-    def initialize(@status, @status_message, @headers, @content_type, @last_modified, @size, @etag, @meta)
+    def initialize(@status, @status_message, @headers)
+    end
+
+    {% for f in ["Cache-Control", "Content-Disposition", "Content-Encoding", "Content-Language", "Content-Type",] %}
+      def {{ f.id.stringify.underscore.gsub(/-/, "_").id }} : String?
+        headers["{{ f.id }}"]?
+      end
+    {% end %}
+
+    def last_modified : Time
+      parse_date(headers["Last-Modified"])
+    end
+
+    def size : UInt64
+      headers["Content-Length"].to_u64
+    end
+
+    def etag : String?
+      headers["ETag"].try{|v| v.strip('"')}
+    end
+
+    def meta : Hash(String, String)
+      meta = {} of String => String
+      response.headers.each do |k, v|
+        next unless k.starts_with?("x-amz-meta-")
+        meta[k.lchop("x-amz-meta-")] = v.first
+      end
+      meta
     end
 
-    private def self.parse_date(date : String)
+    private def parse_date(date : String)
       Time.parse!(date.gsub(/\s{2,}/, ' '), DATE_FORMAT)
     end
   end