[incubator-opendal] branch cpp-more-operation updated: fix missing consume in seek function

[silver]

This is an automated email from the ASF dual-hosted git repository.

silver pushed a commit to branch cpp-more-operation
in repository https://gitbox.apache.org/repos/asf/incubator-opendal.git


The following commit(s) were added to refs/heads/cpp-more-operation by this 
push:
     new eddee4487 fix missing consume in seek function
eddee4487 is described below

commit eddee44870d21763e504af989c5335a0cc3e7367
Author: silver-ymz <yinmingz...@gmail.com>
AuthorDate: Sun Sep 3 23:39:29 2023 +0800

    fix missing consume in seek function
    
    Signed-off-by: silver-ymz <yinmingz...@gmail.com>
---
 bindings/cpp/src/opendal.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/bindings/cpp/src/opendal.cpp b/bindings/cpp/src/opendal.cpp
index 21be52758..6f545a3b3 100644
--- a/bindings/cpp/src/opendal.cpp
+++ b/bindings/cpp/src/opendal.cpp
@@ -93,6 +93,12 @@ ReaderStream Operator::reader(std::string_view path) {
 
 // Reader
 
+// Development Note:
+// Because rust side can't get current pointer info of c++, sowe delay the
+// `consume` operation to the next `fill_buf`. Please pay attention to call
+// `consume` and update c++ pointers before each `seek` and `fill_buf`
+// operation.
+
 ffi::SeekDir to_rust_seek_dir(std::ios_base::seekdir dir);
 
 ReaderStreamBuf::pos_type
@@ -103,6 +109,11 @@ ReaderStreamBuf::seekoff(ReaderStreamBuf::off_type off,
     return -1;
   }
 
+  if (gptr() != nullptr) {
+    reader_->consume(gptr() - eback());
+    setg(gptr(), gptr(), egptr());
+  }
+
   if (dir == std::ios_base::cur) {
     off += gptr() - eback();
   }
@@ -127,6 +138,7 @@ ReaderStreamBuf::seekpos(ReaderStreamBuf::pos_type pos,
 ReaderStreamBuf::int_type ReaderStreamBuf::underflow() {
   if (gptr() != nullptr) {
     reader_->consume(gptr() - eback());
+    setg(gptr(), gptr(), egptr());
   }
   auto buffer = reader_->fill_buf();
   auto gbeg = (char *)(buffer.data());