Revert "refine http data source"

This reverts commit 029f8df.

Author: yoofa

data_source/http_source.h

@@ -23,9 +23,7 @@ class HTTPConnection;
 }
 
 class HTTPSource : public DataSource, public HTTPBase {
- public:
   HTTPSource(std::shared_ptr<net::HTTPConnection> connection);
-  ~HTTPSource() override;
 
   virtual status_t ReconnectAtOffset(off64_t offset);
 
@@ -42,6 +40,9 @@ class HTTPSource : public DataSource, public HTTPBase {
   int32_t Flags() override;
   void Close() override;
 
+ protected:
+  ~HTTPSource() override;
+
   // DataSource interfaces
   std::string GetUri() override;
   virtual std::string GetMIMEType();

net/http/curl_http_connection.cc

@@ -75,15 +75,9 @@ void CurlHttpConnection::Disconnect() {
 }
 
 ssize_t CurlHttpConnection::ReadAt(off64_t offset, void* data, size_t size) {
-  if (!connected_) {
+  if (!connected_ || offset >= content_length_) {
     return -1;
   }
-  const off64_t readable_size = content_length_ >= 0
-                                    ? content_length_
-                                    : static_cast<off64_t>(buffer_.size());
-  if (offset < 0 || offset >= readable_size) {
-    return 0;
-  }
 
   size_t available =
       std::min(size, buffer_.size() - static_cast<size_t>(offset));
@@ -94,8 +88,7 @@ ssize_t CurlHttpConnection::ReadAt(off64_t offset, void* data, size_t size) {
 }
 
 off64_t CurlHttpConnection::GetSize() {
-  return content_length_ >= 0 ? content_length_
-                              : static_cast<off64_t>(buffer_.size());
+  return content_length_;
 }
 
 status_t CurlHttpConnection::GetMIMEType(std::string& mime_type) {