Updating hpfs log index on ledger creation (#274)

src/hpfs/hpfs_mount.cpp

@@ -15,6 +15,7 @@ namespace hpfs
     constexpr const char *RO_SESSION_HMAP = "/::hpfs.ro.hmap.";
     constexpr const char *HMAP_HASH = "::hpfs.hmap.hash";
     constexpr const char *HMAP_CHILDREN = "::hpfs.hmap.children";
+    constexpr const char *INDEX_UPDATE = "/::hpfs.index";
     constexpr ino_t ROOT_INO = 1;
 
     constexpr uint16_t PROCESS_INIT_TIMEOUT = 2000;
@@ -391,4 +392,24 @@ namespace hpfs
         }
     }
 
+    int hpfs_mount::update_hpfs_log_index()
+    {
+        const std::string index_file = mount_dir + INDEX_UPDATE;
+
+        const int fd = open(index_file.c_str(), O_RDWR);
+        if (fd == -1)
+            return -1;
+        
+        // We just send empty buffer with write size 1 to invoke the hpfs index update.
+        // Write syscall isn't invoking with write size 0. 
+        if (write(fd, "", 1) == -1)
+        {
+            close(fd);
+            return -1;
+        }
+
+        close(fd);
+        return 0;
+    }
+
 } // namespace hpfs

src/hpfs/hpfs_mount.hpp

@@ -67,6 +67,7 @@ namespace hpfs
         const std::string physical_path(std::string_view session_name, std::string_view vpath);
         const util::h32 get_parent_hash(const std::string &parent_vpath);
         void set_parent_hash(const std::string &parent_vpath, const util::h32 new_state);
+        int update_hpfs_log_index();
     };
 
 } // namespace hpfs

src/ledger/ledger.cpp

@@ -159,6 +159,13 @@ namespace ledger
         // Update the last shard hash and shard seqence number tracker when a new ledger is created.
         ctx.set_last_primary_shard_id(p2p::sequence_hash{primary_shard_seq_no, last_primary_shard_hash});
 
+        // Update the hpfs log index file only in full history mode.
+        if (conf::cfg.node.history == conf::HISTORY::FULL && sc::contract_fs.update_hpfs_log_index() == -1)
+        {
+            LOG_ERROR << errno << ": Error updating the log index file.";
+            return -1;
+        }
+
         //Remove old shards that exceeds max shard range.
         if (conf::cfg.node.history == conf::HISTORY::CUSTOM && primary_shard_seq_no >= conf::cfg.node.history_config.max_primary_shards)
         {