Add some basic tests for the database

1 files changed, 44 insertions, 3 deletions

diff --git a/src/database/include/records.hpp b/src/database/include/records.hpp
index 22d2ca5b..371d8d58 100644
--- a/src/database/include/records.hpp
+++ b/src/database/include/records.hpp
@@ -1,14 +1,21 @@
 #pragma once
 
-#include <leveldb/db.h>
 #include <stdint.h>
+
 #include <string>
 
+#include "leveldb/db.h"
 #include "leveldb/slice.h"
+
 #include "song.hpp"
 
 namespace database {
 
+/*
+ * Helper class for creating leveldb Slices bundled with the data they point to.
+ * Slices are otherwise non-owning, which can make handling them post-creation
+ * difficult.
+ */
 class OwningSlice {
  public:
   std::string data;
@@ -17,16 +24,50 @@ class OwningSlice {
   explicit OwningSlice(std::string d);
 };
 
+/*
+ * Returns the prefix added to every SongData key. This can be used to iterate
+ * over every data record in the database.
+ */
 auto CreateDataPrefix() -> OwningSlice;
+
+/* Creates a data key for a song with the specified id. */
 auto CreateDataKey(const SongId& id) -> OwningSlice;
+
+/*
+ * Encodes a SongData instance into bytes, in preparation for storing it within
+ * the database. This encoding is consistent, and will remain stable over time.
+ */
 auto CreateDataValue(const SongData& song) -> OwningSlice;
+
+/*
+ * Parses bytes previously encoded via CreateDataValue back into a SongData. May
+ * return nullopt if parsing fails.
+ */
 auto ParseDataValue(const leveldb::Slice& slice) -> std::optional<SongData>;
 
+/* Creates a hash key for the specified hash. */
 auto CreateHashKey(const uint64_t& hash) -> OwningSlice;
-auto ParseHashValue(const leveldb::Slice&) -> std::optional<SongId>;
+
+/*
+ * Encodes a hash value (at this point just a song id) into bytes, in
+ * preparation for storing within the database. This encoding is consistent, and
+ * will remain stable over time.
+ */
 auto CreateHashValue(SongId id) -> OwningSlice;
 
+/*
+ * Parses bytes previously encoded via CreateHashValue back into a song id. May
+ * return nullopt if parsing fails.
+ */
+auto ParseHashValue(const leveldb::Slice&) -> std::optional<SongId>;
+
+/* Encodes a SongId as bytes. */
 auto SongIdToBytes(SongId id) -> OwningSlice;
-auto BytesToSongId(const std::string& bytes) -> SongId;
+
+/*
+ * Converts a song id encoded via SongIdToBytes back into a SongId. May return
+ * nullopt if parsing fails.
+ */
+auto BytesToSongId(const std::string& bytes) -> std::optional<SongId>;
 
 }  // namespace database