rgw.trace.txt 2

rgw.trace.txt

v2
 ## Down the rabbit hole
- check out Yehuda's branch
- "swift and s3 have separate url-to-object translations" - ?

class rgw_obj  # rgw_common.h
  std::string loc;
class RGWGetObj : public RGWOp  # rgw_op.h
  rgw_obj obj;
  map<string, bufferlist> attrs;
class RGWOp   # rgw_op.h
  struct req_state *s; # RGWOp(): s(NULL)
struct req_state # rgw_common.h
  RGWBucketInfo bucket_info;
struct RGWBucketInfo  # rgw_common.h
  rgw_bucket bucket;
struct rgw_bucket  # rgw_common.h
  std::string name;
  std::string data_pool;
  std::string index_pool;
class RGWRados  # rgw_rados.h
  class Object
    RGWBucketInfo bucket_info;  # another one?
    struct Read   # rgw_rados.h:1511
      RGWRados::Object *source;

  process_request(store)
    struct req_state rstate(...), *s = &rstate;
    RGWHandler *handler = rest->get_handler(store, s, client_io, &mgr, &init_error);
    op = handler->get_op(store);

    op->pre_exec();
    op->RGWGetObj::execute()   # rgw_op.cc
      RGWGetObj_CB cb(this);
      # rgw_obj obj - this->obj
      # struct req_state *s; - this->s
      RGWRados::Object op_target(store, s->bucket_info,
        *static_cast<RGWObjectCtx *>(s->obj_ctx), obj);  # bunch of assignments
      RGWRados::Object::Read read_op(source=&op_target); # bunch of assignments
      RGWRados::Object::Read::prepare()  # rgw_rados.cc
        RGWRados *store = source->get_store();
        RGWObjState *astate = source->get_state();
        store->get_obj_ioctx(state.obj = astate->obj, &state.io_ctx);
         RGWRados::get_obj_ioctx(const rgw_obj& obj, librados::IoCtx *ioctx) # rgw_rados.cc
          # XXX wrong hole despite the comment? only opens pool for bucket!
          rgw_bucket bucket;
          string oid, key;
          # obj.bucket.name="testcont" obj.bucket.marker="default.7593.4" obj="imas_cg_rin_3.png"
          void get_obj_bucket_and_oid_loc(const rgw_obj& obj,
           rgw_bucket& bucket, string& oid, string& locator{=key}) # rgw_rados.h
            bucket = obj.bucket;
            prepend_bucket_marker(bucket, obj.get_object(), oid);   # to oid
            prepend_bucket_marker(bucket, obj.get_loc(), locator);
          # at this point oid="default.7593.4_imas_cg_rin_3.png" key=""
          # the underscore is hardcoded in prepend_bucket_marker()
          open_bucket_data_ctx(bucket, *ioctx);
            string& pool = bucket.data_pool;
            open_bucket_pool_ctx(bucket.name, bucket.data_pool, data_ctx);
              RGWRados::open_bucket_pool_ctx(const string& bucket_name,
              const string& pool, librados::IoCtx& io_ctx)  # rgw_rados.cc
                librados::Rados *rad = get_rados_handle();
                rad->ioctx_create(pool.c_str(), io_ctx);
          ioctx->locator_set_key(key);

      ..............
      read_op.iterate(ofs, end, &cb);
    op->complete();