Rename read_bytes() in RecordReader to offset() to avoid misusage and adjust the UT

src/butil/recordio.cc

@@ -210,7 +210,7 @@ int RecordReader::CutRecord(Record* rec) {
     if (*(const uint32_t*)dummy != *(const uint32_t*)BRPC_RECORDIO_MAGIC) {
         LOG(ERROR) << "Invalid magic_num="
                    << butil::PrintedAsBinary(std::string((char*)headbuf, 4))
-                   << ", offset=" << read_bytes();
+                   << ", offset=" << offset();
         return -1;
     }
     uint32_t tmp = NetToHost32(*(const uint32_t*)(headbuf + 4));
@@ -224,7 +224,7 @@ int RecordReader::CutRecord(Record* rec) {
                    << std::hex << tmp << std::dec
                    << "(metabit=" << has_meta
                    << " size=" << data_size
-                   << " offset=" << read_bytes()
+                   << " offset=" << offset()
                    << "), expected=" << (unsigned)headbuf[8]
                    << " actual=" << (unsigned)checksum;
         return -1;
@@ -233,7 +233,7 @@ int RecordReader::CutRecord(Record* rec) {
         LOG(ERROR) << "data_size=" << data_size
                    << " is larger than -recordio_max_record_size="
                    << FLAGS_recordio_max_record_size
-                   << ", offset=" << read_bytes();
+                   << ", offset=" << offset();
         return -1;
     }
     if (_cutter.remaining_bytes() < data_size) {
@@ -257,13 +257,13 @@ int RecordReader::CutRecord(Record* rec) {
         if (consumed_bytes + 5 + name_size + meta_size > data_size) {
             LOG(ERROR) << name << ".meta_size=" << meta_size
                        << " is inconsistent with its data_size=" << data_size
-                       << ", offset=" << read_bytes();
+                       << ", offset=" << offset();
             return -1;
         }
         butil::IOBuf* meta = rec->MutableMeta(name, true/*null_on_found*/);
         if (meta == NULL) {
             LOG(ERROR) << "Fail to add meta=" << name
-                       << ", offset=" << read_bytes();
+                       << ", offset=" << offset();
             return -1;
         }
         _cutter.cutn(meta, meta_size);

src/butil/recordio.h

@@ -102,8 +102,10 @@ public:
     // END_OF_READER means all data in the IReader are successfully consumed.
     int last_error() const { return _last_error; }
 
-    // Total bytes of all read records.
-    size_t read_bytes() const { return _ncut; }
+    // Total bytes consumed.
+    // NOTE: this value may not equal to read bytes from the IReader even if
+    // the reader runs out, due to parsing errors.
+    size_t offset() const { return _ncut; }
 
 private:
     bool CutUntilNextRecordCandidate();

test/recordio_unittest.cpp

@@ -164,7 +164,7 @@ TEST(RecordIOTest, write_read_basic) {
 
     ASSERT_FALSE(rr.ReadNext(NULL));
     ASSERT_EQ((int)butil::RecordReader::END_OF_READER, rr.last_error());
-    ASSERT_EQ(sw.str().size(), rr.read_bytes());
+    ASSERT_EQ(sw.str().size(), rr.offset());
 }
 
 TEST(RecordIOTest, incomplete_reader) {
@@ -208,7 +208,7 @@ TEST(RecordIOTest, incomplete_reader) {
 
     ASSERT_FALSE(rr.ReadNext(NULL));
     ASSERT_EQ(EAGAIN, rr.last_error());
-    ASSERT_EQ(sw.str().size(), rr.read_bytes());
+    ASSERT_EQ(sw.str().size(), rr.offset());
 }
 
 static std::string rand_string(int min_len, int max_len) {
@@ -299,8 +299,8 @@ TEST(RecordIOTest, write_read_random) {
         ASSERT_EQ(name_value_list[j].second, *r.MetaAt(0).data);
     }
     ASSERT_EQ((int)butil::RecordReader::END_OF_READER, rr.last_error());
-    ASSERT_EQ(str.size(), rr.read_bytes());
     ASSERT_EQ(j, name_value_list.size());
+    ASSERT_LE(str.size() - rr.offset(), 3);
 }
 
 } // namespace