Add compressed requests (#739)

* Add optional compression of the request's content

This option allows compression of the files and/or data during uploading,

Examples:

    http --form --compress POST https://localhost/upload csv@./very-big.csv

    http -x -x POST https://localhost/upload foo=bar

    cat /var/log/system.log | http -x POST https://localhost/upload

Signed-off-by: Aleksandr Vinokurov <aleksandr.vin@gmail.com>

* Add tests for compression

Signed-off-by: Aleksandr Vinokurov <aleksandr.vin@gmail.com>

* Fix code style issues

Signed-off-by: Aleksandr Vinokurov <aleksandr.vin@gmail.com>

* Fix zlib compression api missuse in Python3

Signed-off-by: Aleksandr Vinokurov <aleksandr.vin@gmail.com>

* Remove tracing from compression logic

Signed-off-by: Aleksandr Vinokurov <aleksandr.vin@gmail.com>

tests/test_httpie.py

@@ -49,12 +49,28 @@ def test_POST_JSON_data(httpbin_both):
     assert r.json['json']['foo'] == 'bar'
 
 
+def test_POST_JSON_data_compressed(httpbin_both):
+    r = http('--compress', '--compress', 'POST', httpbin_both + '/post', 'foo=bar')
+    assert HTTP_OK in r
+    assert r.json['headers']['Content-Encoding'] == 'deflate'
+    assert r.json['data'].startswith('data:application/octet-stream;')
+    assert r.json['json'] is None
+
+
 def test_POST_form(httpbin_both):
     r = http('--form', 'POST', httpbin_both + '/post', 'foo=bar')
     assert HTTP_OK in r
     assert '"foo": "bar"' in r
 
 
+def test_POST_form_compressed(httpbin_both):
+    r = http('--form', '--compress', '--compress', 'POST', httpbin_both + '/post', 'foo=bar')
+    assert HTTP_OK in r
+    assert r.json['headers']['Content-Encoding'] == 'deflate'
+    assert r.json['data'] == ""
+    assert '"foo": "bar"' not in r
+
+
 def test_POST_form_multiple_values(httpbin_both):
     r = http('--form', 'POST', httpbin_both + '/post', 'foo=bar', 'foo=baz')
     assert HTTP_OK in r
@@ -69,6 +85,31 @@ def test_POST_stdin(httpbin_both):
     assert FILE_CONTENT in r
 
 
+def test_POST_stdin_compressed(httpbin_both):
+    with open(FILE_PATH) as f:
+        env = MockEnvironment(stdin=f, stdin_isatty=False)
+        r = http('--form', '--compress', '--compress', 'POST', httpbin_both + '/post', env=env)
+    assert HTTP_OK in r
+    assert r.json['headers']['Content-Encoding'] == 'deflate'
+    assert r.json['data'] == ""
+    assert FILE_CONTENT not in r
+
+
+def test_POST_file(httpbin_both):
+    r = http('--form', 'POST', httpbin_both + '/post', 'file@' + FILE_PATH)
+    assert HTTP_OK in r
+    assert FILE_CONTENT in r
+
+
+def test_POST_file_compressed(httpbin_both):
+    r = http('--form', '--compress', '--compress', 'POST', httpbin_both + '/post', 'file@' + FILE_PATH)
+    assert HTTP_OK in r
+    assert r.json['headers']['Content-Encoding'] == 'deflate'
+    assert r.json['headers']['Content-Type'].startswith('multipart/form-data; boundary=')
+    assert r.json['files'] == {}
+    assert FILE_CONTENT not in r
+
+
 def test_headers(httpbin_both):
     r = http('GET', httpbin_both + '/headers', 'Foo:bar')
     assert HTTP_OK in r