change http body_writer return type to ssize_t (#197)

Signed-off-by: liulanzheng <lanzheng.liulz@alibaba-inc.com>

net/http/client.h

@@ -48,9 +48,9 @@ class Client : public Object {
  Response resp; // response
  int status_code = -1; // status code in response
  bool enable_proxy;
- IStream* body_stream = nullptr; // use body_stream as body
- using BodyWriter = Callback<Request*>;  // or call body_writer if body_stream
- BodyWriter body_writer = {}; // is not set
+ IStream* body_stream = nullptr;  // use body_stream as body
+ using BodyWriter = Delegate<ssize_t, Request*>; // or call body_writer if body_stream
+ BodyWriter body_writer = {};  // is not set
 
  static Operation* create(Client* c, Verb v, std::string_view url,
  uint16_t buf_size = 64 * 1024 - 1) {

net/http/test/client_function_test.cpp

@@ -186,7 +186,7 @@ TEST(http_client, post) {
  auto op2 = client->new_operation(Verb::POST, target);
  DEFER(delete op2);
  op2->req.headers.content_length(st.st_size);
- auto writer = [&](Request *req)-> int {
+ auto writer = [&](Request *req)-> ssize_t {
  file->lseek(0, SEEK_SET);
  return req->write_stream(file, st.st_size);
  };

net/http/test/server_function_test.cpp

@@ -109,7 +109,7 @@ TEST(http_server, post) {
  DEFER(delete op);
  op->req.headers.content_length(10);
  std::string body = "1234567890";
- auto writer = [&](Request *req)-> int {
+ auto writer = [&](Request *req)-> ssize_t {
  return req->write(body.data(), body.size());
  };
  op->body_writer = writer;
@@ -343,7 +343,7 @@ TEST(http_server, proxy_handler_post) {
  DEFER(delete op);
  std::string body = "1234567890";
  op->req.headers.content_length(10);
- auto writer = [&](Request *req)-> int {
+ auto writer = [&](Request *req)-> ssize_t {
  return req->write(body.data(), body.size());
  };
  op->body_writer = writer;
@@ -405,7 +405,7 @@ TEST(http_server, proxy_handler_post_forward) {
  DEFER(delete op);
  std::string body = "1234567890";
  op->req.headers.content_length(10);
- auto writer = [&](Request *req)-> int {
+ auto writer = [&](Request *req)-> ssize_t {
  return req->write(body.data(), body.size());
  };
  op->body_writer = writer;