AWS S3 IO through KvikIO

cpp/src/io/utilities/datasource.cpp

@@ -26,13 +26,15 @@
 #include <cudf/utilities/span.hpp>
 
 #include <kvikio/file_handle.hpp>
+#include <kvikio/remote_handle.hpp>
 
 #include <rmm/device_buffer.hpp>
 
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
 
+#include <regex>
 #include <vector>
 
 namespace cudf {
@@ -389,6 +391,86 @@ class user_datasource_wrapper : public datasource {
   datasource* const source;  ///< A non-owning pointer to the user-implemented datasource
 };
 
+/**
+ * @brief Remote file source backed by KvikIO, which handles S3 filepaths seamlessly.
+ */
+class remote_file_source : public datasource {
+  static std::unique_ptr<kvikio::S3Endpoint> create_s3_endpoint(char const* filepath)
+  {
+    auto [bucket_name, bucket_object] = kvikio::S3Endpoint::parse_s3_url(filepath);
+    return std::make_unique<kvikio::S3Endpoint>(bucket_name, bucket_object);
+  }
+
+ public:
+  explicit remote_file_source(char const* filepath) : _kvikio_file{create_s3_endpoint(filepath)} {}
+
+  ~remote_file_source() override = default;
+
+  [[nodiscard]] bool supports_device_read() const override { return true; }
+
+  [[nodiscard]] bool is_device_read_preferred(size_t size) const override { return true; }
+
+  [[nodiscard]] size_t size() const override { return _kvikio_file.nbytes(); }
+
+  std::future<size_t> device_read_async(size_t offset,
+                                        size_t size,
+                                        uint8_t* dst,
+                                        rmm::cuda_stream_view stream) override
+  {
+    CUDF_EXPECTS(supports_device_read(), "Device reads are not supported for this file.");
+
+    auto const read_size = std::min(size, this->size() - offset);
+    return _kvikio_file.pread(dst, read_size, offset);
+  }
+
+  size_t device_read(size_t offset,
+                     size_t size,
+                     uint8_t* dst,
+                     rmm::cuda_stream_view stream) override
+  {
+    return device_read_async(offset, size, dst, stream).get();
+  }
+
+  std::unique_ptr<datasource::buffer> device_read(size_t offset,
+                                                  size_t size,
+                                                  rmm::cuda_stream_view stream) override
+  {
+    rmm::device_buffer out_data(size, stream);
+    size_t read = device_read(offset, size, reinterpret_cast<uint8_t*>(out_data.data()), stream);
+    out_data.resize(read, stream);
+    return datasource::buffer::create(std::move(out_data));
+  }
+
+  size_t host_read(size_t offset, size_t size, uint8_t* dst) override
+  {
+    auto const read_size = std::min(size, this->size() - offset);
+    return _kvikio_file.pread(dst, read_size, offset).get();
+  }
+
+  std::unique_ptr<buffer> host_read(size_t offset, size_t size) override
+  {
+    auto const count = std::min(size, this->size() - offset);
+    std::vector<uint8_t> h_data(count);
+    this->host_read(offset, count, h_data.data());
+    return datasource::buffer::create(std::move(h_data));
+  }
+
+  /**
+   * @brief Is `url` referring to a remote file supported by KvikIO?
+   *
+   * For now, only S3 urls (urls starting with "s3://") are supported.
+   */
+  static bool is_supported_remote_url(std::string const& url)
+  {
+    // Regular expression to match "s3://"
+    std::regex pattern{R"(^s3://)", std::regex_constants::icase};
+    return std::regex_search(url, pattern);
+  }
+
+ private:
+  kvikio::RemoteHandle _kvikio_file;
+};
+
 }  // namespace
 
 std::unique_ptr<datasource> datasource::create(std::string const& filepath,
@@ -403,8 +485,9 @@ std::unique_ptr<datasource> datasource::create(std::string const& filepath,
 
     CUDF_FAIL("Invalid LIBCUDF_MMAP_ENABLED value: " + policy);
   }();
-
-  if (use_memory_mapping) {
+  if (remote_file_source::is_supported_remote_url(filepath)) {
+    return std::make_unique<remote_file_source>(filepath.c_str());
+  } else if (use_memory_mapping) {
     return std::make_unique<memory_mapped_source>(filepath.c_str(), offset, max_size_estimate);
   } else {
     // `file_source` reads the file directly, without memory mapping

python/cudf/cudf/options.py

@@ -351,6 +351,22 @@ def _integer_and_none_validator(val):
     _make_contains_validator([False, True]),
 )
 
+_register_option(
+    "kvikio_remote_io",
+    _env_get_bool("CUDF_KVIKIO_REMOTE_IO", False),
+    textwrap.dedent(
+        """
+        Whether to use KvikIO's remote IO backend or not.
+        \tWARN: this is experimental and may be removed at any time
+        \twithout warning or deprecation period.
+        \tSet KVIKIO_NTHREADS (default is 8) to change the number of
+        \tconcurrent tcp connections, which is important for good performance.
+        \tValid values are True or False. Default is False.
+    """
+    ),
+    _make_contains_validator([False, True]),
+)
+
 
 class option_context(ContextDecorator):
     """

python/cudf/cudf/tests/test_s3.py

@@ -69,6 +69,7 @@ def s3_base(endpoint_ip, endpoint_port):
         # with an S3 endpoint on localhost
 
         endpoint_uri = f"http://{endpoint_ip}:{endpoint_port}/"
+        os.environ["AWS_ENDPOINT_URL"] = endpoint_uri
 
         server = ThreadedMotoServer(ip_address=endpoint_ip, port=endpoint_port)
         server.start()
@@ -105,6 +106,15 @@ def s3_context(s3_base, bucket, files=None):
                 pass
 
 
+@pytest.fixture(
+    params=[True, False],
+    ids=["kvikio=ON", "kvikio=OFF"],
+)
+def kvikio_remote_io(request):
+    with cudf.option_context("kvikio_remote_io", request.param):
+        yield request.param
+
+
 @pytest.fixture
 def pdf(scope="module"):
     df = pd.DataFrame()
@@ -193,6 +203,7 @@ def test_write_csv(s3_base, s3so, pdf, chunksize):
 def test_read_parquet(
     s3_base,
     s3so,
+    kvikio_remote_io,
     pdf,
     bytes_per_thread,
     columns,

python/cudf/cudf/utils/ioutils.py

@@ -16,6 +16,7 @@
 import pandas as pd
 from fsspec.core import expand_paths_if_needed, get_fs_token_paths
 
+import cudf
 from cudf.api.types import is_list_like
 from cudf.core._compat import PANDAS_LT_300
 from cudf.utils.docutils import docfmt_partial
@@ -1624,6 +1625,16 @@ def _maybe_expand_directories(paths, glob_pattern, fs):
     return expanded_paths
 
 
+def _use_kvikio_remote_io(fs) -> bool:
+    """Whether `kvikio_remote_io` is enabled and `fs` refers to a S3 file"""
+
+    try:
+        from s3fs.core import S3FileSystem
+    except ImportError:
+        return False
+    return cudf.get_option("kvikio_remote_io") and isinstance(fs, S3FileSystem)
+
+
 @doc_get_reader_filepath_or_buffer()
 def get_reader_filepath_or_buffer(
     path_or_data,
@@ -1649,17 +1660,17 @@ def get_reader_filepath_or_buffer(
         )
     ]
     if not input_sources:
-        raise ValueError("Empty input source list: {input_sources}.")
+        raise ValueError(f"Empty input source list: {input_sources}.")
 
     filepaths_or_buffers = []
     string_paths = [isinstance(source, str) for source in input_sources]
     if any(string_paths):
-        # Sources are all strings. Thes strings are typically
+        # Sources are all strings. The strings are typically
         # file paths, but they may also be raw text strings.
 
         # Don't allow a mix of source types
         if not all(string_paths):
-            raise ValueError("Invalid input source list: {input_sources}.")
+            raise ValueError(f"Invalid input source list: {input_sources}.")
 
         # Make sure we define a filesystem (if possible)
         paths = input_sources
@@ -1712,11 +1723,17 @@ def get_reader_filepath_or_buffer(
                 raise FileNotFoundError(
                     f"{input_sources} could not be resolved to any files"
                 )
-            filepaths_or_buffers = _prefetch_remote_buffers(
-                paths,
-                fs,
-                **(prefetch_options or {}),
-            )
+
+            # If `kvikio_remote_io` is enabled and `fs` refers to a S3 file,
+            # we create S3 URLs and let them pass-through to libcudf.
+            if _use_kvikio_remote_io(fs):
+                filepaths_or_buffers = [f"s3://{fpath}" for fpath in paths]
+            else:
+                filepaths_or_buffers = _prefetch_remote_buffers(
+                    paths,
+                    fs,
+                    **(prefetch_options or {}),
+                )
         else:
             raw_text_input = True
 

python/pylibcudf/pylibcudf/io/types.pyx

@@ -20,6 +20,7 @@ import codecs
 import errno
 import io
 import os
+import re
 
 from pylibcudf.libcudf.io.json import \
     json_recovery_mode_t as JSONRecoveryMode  # no-cython-lint
@@ -143,6 +144,8 @@ cdef class SourceInfo:
 
         Mixing different types of sources will raise a `ValueError`.
     """
+    # Regular expression that match remote file paths supported by libcudf
+    _is_remote_file_pattern = re.compile(r"^s3://", re.IGNORECASE)
 
     def __init__(self, list sources):
         if not sources:
@@ -157,11 +160,10 @@ cdef class SourceInfo:
             for src in sources:
                 if not isinstance(src, (os.PathLike, str)):
                     raise ValueError("All sources must be of the same type!")
-                if not os.path.isfile(src):
-                    raise FileNotFoundError(errno.ENOENT,
-                                            os.strerror(errno.ENOENT),
-                                            src)
-
+                if not (os.path.isfile(src) or self._is_remote_file_pattern.match(src)):
+                    raise FileNotFoundError(
+                        errno.ENOENT, os.strerror(errno.ENOENT), src
+                    )
                 c_files.push_back(<string> str(src).encode())
 
             self.c_obj = move(source_info(c_files))