feat: add filesystem_v2::cache_blocks_by_category()

include/dwarfs/reader/filesystem_v2.h

@@ -357,6 +357,10 @@ class filesystem_v2 {
     return impl_->get_block_category(block_number);
   }
 
+  void cache_blocks_by_category(std::string_view category) const {
+    return impl_->cache_blocks_by_category(category);
+  }
+
   class impl {
    public:
     virtual ~impl() = default;
@@ -452,6 +456,7 @@ class filesystem_v2 {
     virtual std::shared_ptr<internal::filesystem_parser> get_parser() const = 0;
     virtual std::optional<std::string>
     get_block_category(size_t block_number) const = 0;
+    virtual void cache_blocks_by_category(std::string_view category) const = 0;
   };
 
  private:

include/dwarfs/reader/internal/inode_reader_v2.h

@@ -31,6 +31,7 @@
 #include <cstddef>
 #include <iosfwd>
 #include <memory>
+#include <span>
 #include <string>
 #include <system_error>
 #include <vector>
@@ -100,6 +101,10 @@ class inode_reader_v2 {
 
   size_t num_blocks() const { return impl_->num_blocks(); }
 
+  void cache_blocks(std::span<size_t const> blocks) const {
+    impl_->cache_blocks(blocks);
+  }
+
   class impl {
    public:
     virtual ~impl() = default;
@@ -121,6 +126,7 @@ class inode_reader_v2 {
     virtual void set_num_workers(size_t num) = 0;
     virtual void set_cache_tidy_config(cache_tidy_config const& cfg) = 0;
     virtual size_t num_blocks() const = 0;
+    virtual void cache_blocks(std::span<size_t const> blocks) const = 0;
   };
 
  private:

include/dwarfs/reader/internal/metadata_v2.h

@@ -184,6 +184,11 @@ class metadata_v2 {
     return impl_->get_all_gids();
   }
 
+  std::vector<size_t>
+  get_block_numbers_by_category(std::string_view category) const {
+    return impl_->get_block_numbers_by_category(category);
+  }
+
   class impl {
    public:
     virtual ~impl() = default;
@@ -255,6 +260,9 @@ class metadata_v2 {
     virtual std::vector<file_stat::uid_type> get_all_uids() const = 0;
 
     virtual std::vector<file_stat::gid_type> get_all_gids() const = 0;
+
+    virtual std::vector<size_t>
+    get_block_numbers_by_category(std::string_view category) const = 0;
   };
 
  private:

src/reader/filesystem_v2.cpp

@@ -312,6 +312,10 @@ class filesystem_ final : public filesystem_v2::impl {
     return meta_.get_block_category(block_no);
   }
 
+  void cache_blocks_by_category(std::string_view category) const override {
+    ir_.cache_blocks(meta_.get_block_numbers_by_category(category));
+  }
+
  private:
   filesystem_info const* get_info(fsinfo_options const& opts) const;
   void check_section(fs_section const& section) const;

src/reader/internal/block_cache.cpp

@@ -722,6 +722,8 @@ class block_cache_ final : public block_cache::impl {
         block->touch();
       }
 
+      LOG_VERBOSE << "inserting block " << block_no << " into cache";
+
       cache_.set(block_no, std::move(block));
     }
   }

src/reader/internal/inode_reader_v2.cpp

@@ -152,6 +152,12 @@ class inode_reader_ final : public inode_reader_v2::impl {
   }
   size_t num_blocks() const override { return cache_.block_count(); }
 
+  void cache_blocks(std::span<size_t const> blocks) const override {
+    for (auto b : blocks) {
+      cache_.get(b, 0, 1);
+    }
+  }
+
  private:
   using offset_cache_type =
       basic_offset_cache<uint32_t, file_off_t, size_t,

src/reader/internal/metadata_v2.cpp

@@ -563,6 +563,9 @@ class metadata_ final : public metadata_v2::impl {
   std::vector<file_stat::uid_type> get_all_uids() const override;
   std::vector<file_stat::gid_type> get_all_gids() const override;
 
+  std::vector<size_t>
+  get_block_numbers_by_category(std::string_view category) const override;
+
  private:
   template <typename K>
   using set_type = folly::F14ValueSet<K>;
@@ -2203,6 +2206,35 @@ std::vector<file_stat::gid_type> metadata_<LoggerPolicy>::get_all_gids() const {
   return rv;
 }
 
+template <typename LoggerPolicy>
+std::vector<size_t> metadata_<LoggerPolicy>::get_block_numbers_by_category(
+    std::string_view category) const {
+  std::vector<size_t> rv;
+
+  if (auto catnames = meta_.category_names()) {
+    if (auto categories = meta_.block_categories()) {
+      std::optional<size_t> category_num;
+
+      for (size_t catnum = 0; catnum < catnames.value().size(); ++catnum) {
+        if (catnames.value()[catnum] == category) {
+          category_num = catnum;
+          break;
+        }
+      }
+
+      if (category_num) {
+        for (size_t blknum = 0; blknum < categories.value().size(); ++blknum) {
+          if (categories.value()[blknum] == *category_num) {
+            rv.push_back(blknum);
+          }
+        }
+      }
+    }
+  }
+
+  return rv;
+}
+
 metadata_v2::metadata_v2(
     logger& lgr, std::span<uint8_t const> schema, std::span<uint8_t const> data,
     metadata_options const& options, int inode_offset,