refactor: allow replacing folly::small_vector with alternatives

include/dwarfs/entry.h

@@ -33,10 +33,9 @@
 #include <unordered_map>
 #include <vector>
 
-#include <folly/small_vector.h>
-
 #include <dwarfs/entry_interface.h>
 #include <dwarfs/file_stat.h>
+#include <dwarfs/small_vector.h>
 
 namespace dwarfs {
 
@@ -151,7 +150,7 @@ class file : public entry {
 
  private:
   struct data {
-    using hash_type = folly::small_vector<char, 16>;
+    using hash_type = small_vector<char, 16>;
     hash_type hash;
     uint32_t refcount{1};
     std::optional<uint32_t> inode_num;

include/dwarfs/inode.h

@@ -28,11 +28,10 @@
 #include <tuple>
 #include <vector>
 
-#include <folly/small_vector.h>
-
 #include <dwarfs/inode_fragments.h>
 #include <dwarfs/nilsimsa.h>
 #include <dwarfs/object.h>
+#include <dwarfs/small_vector.h>
 #include <dwarfs/sortable_span.h>
 
 namespace dwarfs {
@@ -50,7 +49,7 @@ struct inode_options;
 
 class inode : public object {
  public:
-  using files_vector = folly::small_vector<file*, 1>;
+  using files_vector = small_vector<file*, 1>;
 
   virtual void set_files(files_vector&& fv) = 0;
   virtual void populate(size_t size) = 0;

include/dwarfs/inode_fragments.h

@@ -27,9 +27,8 @@
 #include <string>
 #include <unordered_map>
 
-#include <folly/small_vector.h>
-
 #include <dwarfs/fragment_category.h>
+#include <dwarfs/small_vector.h>
 #include <dwarfs/types.h>
 
 #include <dwarfs/gen-cpp2/metadata_types.h>
@@ -57,7 +56,7 @@ class single_inode_fragment {
  private:
   fragment_category category_;
   file_off_t length_;
-  folly::small_vector<thrift::metadata::chunk, 1> chunks_;
+  small_vector<thrift::metadata::chunk, 1> chunks_;
 };
 
 class inode_fragments {
@@ -105,7 +104,7 @@ class inode_fragments {
   std::unordered_map<fragment_category, file_off_t> get_category_sizes() const;
 
  private:
-  folly::small_vector<single_inode_fragment, 1> fragments_;
+  small_vector<single_inode_fragment, 1> fragments_;
 };
 
 inline std::ostream& operator<<(std::ostream& os, inode_fragments const& frag) {

include/dwarfs/iovec_read_buf.h

@@ -22,9 +22,9 @@
 #pragma once
 
 #include <folly/portability/IOVec.h>
-#include <folly/small_vector.h>
 
 #include <dwarfs/block_range.h>
+#include <dwarfs/small_vector.h>
 
 namespace dwarfs {
 
@@ -32,8 +32,8 @@ struct iovec_read_buf {
   // This covers more than 95% of reads
   static constexpr size_t inline_storage = 16;
 
-  folly::small_vector<struct ::iovec, inline_storage> buf;
-  folly::small_vector<block_range, inline_storage> ranges;
+  small_vector<struct ::iovec, inline_storage> buf;
+  small_vector<block_range, inline_storage> ranges;
 };
 
 } // namespace dwarfs

include/dwarfs/offset_cache.h

@@ -30,7 +30,8 @@
 #include <vector>
 
 #include <folly/container/EvictingCacheMap.h>
-#include <folly/small_vector.h>
+
+#include <dwarfs/small_vector.h>
 
 namespace dwarfs {
 
@@ -153,7 +154,7 @@ class basic_offset_cache {
     std::span<file_offset_type const> offsets() const { return offsets_; }
 
    private:
-    folly::small_vector<file_offset_type, max_inline_offsets> offsets_;
+    small_vector<file_offset_type, max_inline_offsets> offsets_;
     chunk_index_type first_index_{0};
   };
 

include/dwarfs/performance_monitor.h

@@ -31,7 +31,7 @@
 #include <string>
 #include <unordered_set>
 
-#include <folly/small_vector.h>
+#include <dwarfs/small_vector.h>
 
 namespace dwarfs {
 
@@ -95,7 +95,7 @@ class performance_monitor_proxy {
     performance_monitor::timer_id id_;
     performance_monitor::time_type start_;
     std::optional<
-        folly::small_vector<uint64_t, performance_monitor::kNumInlineContext>>
+        small_vector<uint64_t, performance_monitor::kNumInlineContext>>
         context_;
   };
 

include/dwarfs/small_vector.h

@@ -0,0 +1,33 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/**
+ * \author     Marcus Holland-Moritz (github@mhxnet.de)
+ * \copyright  Copyright (c) Marcus Holland-Moritz
+ *
+ * This file is part of dwarfs.
+ *
+ * dwarfs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * dwarfs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with dwarfs.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <folly/small_vector.h>
+// #include <boost/container/small_vector.hpp>
+
+namespace dwarfs {
+
+template <typename T, size_t N>
+using small_vector = folly::small_vector<T, N>;
+// using small_vector = boost::container::small_vector<T, N>;
+
+} // namespace dwarfs

src/dwarfs/inode_manager.cpp

@@ -39,7 +39,6 @@
 
 #include <folly/Demangle.h>
 #include <folly/String.h>
-#include <folly/small_vector.h>
 #include <folly/sorted_vector_types.h>
 
 #include <dwarfs/categorizer.h>

src/dwarfs/performance_monitor.cpp

@@ -137,7 +137,7 @@ class performance_monitor_impl : public performance_monitor {
     timer_id id;
     time_type start;
     time_type end;
-    folly::small_vector<uint64_t, kNumInlineContext> context;
+    small_vector<uint64_t, kNumInlineContext> context;
   };
 
   explicit performance_monitor_impl(