Add fallback code for older AWS SDK versions

cpp/src/arrow/filesystem/s3fs.cc

@@ -56,8 +56,6 @@
 #include <aws/core/utils/xml/XmlSerializer.h>
 #include <aws/identity-management/auth/STSAssumeRoleCredentialsProvider.h>
 #include <aws/s3/S3Client.h>
-#include <aws/s3/S3ClientConfiguration.h>
-#include <aws/s3/S3EndpointProvider.h>
 #include <aws/s3/S3Errors.h>
 #include <aws/s3/model/AbortMultipartUploadRequest.h>
 #include <aws/s3/model/CompleteMultipartUploadRequest.h>
@@ -101,12 +99,21 @@
 #define ARROW_S3_HAS_CRT
 #endif
 
+#if ARROW_AWS_SDK_VERSION_CHECK(1, 10, 0)
+#define ARROW_S3_HAS_S3CLIENT_CONFIGURATION
+#endif
+
 #ifdef ARROW_S3_HAS_CRT
 #include <aws/crt/io/Bootstrap.h>
 #include <aws/crt/io/EventLoopGroup.h>
 #include <aws/crt/io/HostResolver.h>
 #endif
 
+#ifdef ARROW_S3_HAS_S3CLIENT_CONFIGURATION
+#include <aws/s3/S3ClientConfiguration.h>
+#include <aws/s3/S3EndpointProvider.h>
+#endif
+
 #include "arrow/util/windows_fixup.h"
 
 #include "arrow/buffer.h"
@@ -913,6 +920,18 @@ Result<std::shared_ptr<S3ClientHolder>> GetClientHolder(
 // -----------------------------------------------------------------------
 // S3 client factory: build S3Client from S3Options
 
+#ifdef ARROW_S3_HAS_S3CLIENT_CONFIGURATION
+
+// GH-40279: standard initialization of S3Client creates a new `S3EndpointProvider`
+// every time. Its construction takes 1ms, which makes instantiating every S3Client
+// very costly (see upstream bug report
+// at https://github.com/aws/aws-sdk-cpp/issues/2880).
+// To work around this, we build and cache `S3EndpointProvider` instances
+// for each distinct endpoint configuration, and reuse them whenever possible.
+// Since most applications tend to use a single endpoint configuration, this
+// makes the 1ms setup cost a once-per-process overhead, making it much more
+// bearable - if not ideal.
+
 struct EndpointConfigKey {
   explicit EndpointConfigKey(const Aws::S3::S3ClientConfiguration& config)
       : region(config.region),
@@ -938,6 +957,7 @@ struct EndpointConfigKey {
 template <>
 struct std::hash<arrow::fs::EndpointConfigKey> {
   std::size_t operator()(const arrow::fs::EndpointConfigKey& key) const noexcept {
+    // A crude hash is sufficient since we expect the cache to remain very small.
     auto h = std::hash<Aws::String>{};
     return h(key.region) ^ h(key.endpoint_override);
   }
@@ -946,15 +966,17 @@ struct std::hash<arrow::fs::EndpointConfigKey> {
 namespace arrow::fs {
 namespace {
 
+// EndpointProvider configuration happens in a non-thread-safe way, even
+// when the updates are idempotent. This is a problem when trying to reuse
+// a single EndpointProvider from several clients.
+// To work around this, this class ensures reconfiguration of an existing
+// EndpointProvider is a no-op.
 class InitOnceEndpointProvider : public Aws::S3::S3EndpointProviderBase {
  public:
   explicit InitOnceEndpointProvider(
       std::shared_ptr<Aws::S3::S3EndpointProviderBase> wrapped)
       : wrapped_(std::move(wrapped)) {}
 
-  // EndpointProvider configuration happens in a non-thread-safe way, even
-  // when the updates are idempotent. To work around this, this class ensures
-  // reconfiguration of an existing EndpointProvider is a no-op.
   void InitBuiltInParameters(const Aws::S3::S3ClientConfiguration& config) override {}
 
   void OverrideEndpoint(const Aws::String& endpoint) override {
@@ -980,6 +1002,9 @@ class InitOnceEndpointProvider : public Aws::S3::S3EndpointProviderBase {
   std::shared_ptr<Aws::S3::S3EndpointProviderBase> wrapped_;
 };
 
+// A class that instantiates a single EndpointProvider per distinct endpoint
+// configuration and initializes it in a thread-safe way. See earlier comments
+// for rationale.
 class EndpointProviderBuilder {
  public:
   std::shared_ptr<Aws::S3::S3EndpointProviderBase> Lookup(
@@ -1021,6 +1046,8 @@ class EndpointProviderBuilder {
   std::unordered_map<EndpointConfigKey, CacheValue> cache_;
 };
 
+#endif  // ARROW_S3_HAS_S3CLIENT_CONFIGURATION
+
 class ClientBuilder {
  public:
   explicit ClientBuilder(S3Options options) : options_(std::move(options)) {}
@@ -1045,8 +1072,6 @@ class ClientBuilder {
           static_cast<long>(ceil(options_.connect_timeout * 1000));  // NOLINT runtime/int
     }
 
-    client_config_.useVirtualAddressing =
-        options_.endpoint_override.empty() || options_.force_virtual_addressing;
     client_config_.endpointOverride = ToAwsString(options_.endpoint_override);
     if (options_.scheme == "http") {
       client_config_.scheme = Aws::Http::Scheme::HTTP;
@@ -1097,10 +1122,20 @@ class ClientBuilder {
       client_config_.maxConnections = std::max(io_context->executor()->GetCapacity(), 25);
     }
 
+    const bool use_virtual_addressing =
+        options_.endpoint_override.empty() || options_.force_virtual_addressing;
+
+#ifdef ARROW_S3_HAS_S3CLIENT_CONFIGURATION
+    client_config_.useVirtualAddressing = use_virtual_addressing;
     auto endpoint_provider = EndpointProviderBuilder::Instance()->Lookup(client_config_);
     auto client = std::make_shared<S3Client>(credentials_provider_, endpoint_provider,
                                              client_config_);
-
+#else
+    auto client = std::make_shared<S3Client>(
+        credentials_provider_, client_config_,
+        Aws::Client::AWSAuthV4Signer::PayloadSigningPolicy::Never,
+        use_virtual_addressing);
+#endif
     client->s3_retry_strategy_ = options_.retry_strategy;
     return GetClientHolder(std::move(client));
   }
@@ -1109,7 +1144,11 @@ class ClientBuilder {
 
  protected:
   S3Options options_;
+#ifdef ARROW_S3_HAS_S3CLIENT_CONFIGURATION
   Aws::S3::S3ClientConfiguration client_config_;
+#else
+  Aws::Client::ClientConfiguration client_config_;
+#endif
   std::shared_ptr<Aws::Auth::AWSCredentialsProvider> credentials_provider_;
 };
 
@@ -3056,7 +3095,9 @@ struct AwsInstance {
                "This could lead to a segmentation fault at exit";
       }
       GetClientFinalizer()->Finalize();
+#ifdef ARROW_S3_HAS_S3CLIENT_CONFIGURATION
       EndpointProviderBuilder::Instance()->Reset();
+#endif
       Aws::ShutdownAPI(aws_options_);
     }
   }