diff options
Diffstat (limited to 'Timeline')
| -rw-r--r-- | Timeline/Entities/DataEntity.cs | 23 | ||||
| -rw-r--r-- | Timeline/Entities/DatabaseContext.cs | 1 | ||||
| -rw-r--r-- | Timeline/Services/DataManager.cs | 122 |
3 files changed, 107 insertions, 39 deletions
diff --git a/Timeline/Entities/DataEntity.cs b/Timeline/Entities/DataEntity.cs new file mode 100644 index 00000000..b21e2dbf --- /dev/null +++ b/Timeline/Entities/DataEntity.cs @@ -0,0 +1,23 @@ +using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace Timeline.Entities
+{
+ [Table("data")]
+ public class DataEntity
+ {
+ [Column("id"), Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
+ public long Id { get; set; }
+
+ [Column("tag"), Required]
+ public string Tag { get; set; } = default!;
+
+ [Column("data"), Required]
+#pragma warning disable CA1819 // Properties should not return arrays
+ public byte[] Data { get; set; } = default!;
+#pragma warning restore CA1819 // Properties should not return arrays
+
+ [Column("ref"), Required]
+ public int Ref { get; set; }
+ }
+}
diff --git a/Timeline/Entities/DatabaseContext.cs b/Timeline/Entities/DatabaseContext.cs index 039cbd51..3ed61b71 100644 --- a/Timeline/Entities/DatabaseContext.cs +++ b/Timeline/Entities/DatabaseContext.cs @@ -21,5 +21,6 @@ namespace Timeline.Entities public DbSet<TimelinePostEntity> TimelinePosts { get; set; } = default!;
public DbSet<TimelineMemberEntity> TimelineMembers { get; set; } = default!;
public DbSet<JwtTokenEntity> JwtToken { get; set; } = default!;
+ public DbSet<DataEntity> Data { get; set; } = default!;
}
}
diff --git a/Timeline/Services/DataManager.cs b/Timeline/Services/DataManager.cs index 005ad23c..66aa6f81 100644 --- a/Timeline/Services/DataManager.cs +++ b/Timeline/Services/DataManager.cs @@ -1,37 +1,19 @@ -using System;
-using System.Collections.Generic;
+using Microsoft.EntityFrameworkCore;
+using System;
using System.Linq;
using System.Threading.Tasks;
+using Timeline.Entities;
namespace Timeline.Services
{
- public class DataEntry
- {
-#pragma warning disable CA1819 // Properties should not return arrays
- public byte[] Data { get; set; } = default!;
-#pragma warning restore CA1819 // Properties should not return arrays
- public DataInfo Info { get; set; } = default!;
- }
-
- public class DataInfo
- {
- public DateTime Time { get; set; }
- public string Type { get; set; } = default!;
- }
-
/// <summary>
- /// A data manager controling data.
+ /// A data manager controlling data.
/// </summary>
/// <remarks>
- /// All data to be saved will be checked identity.
/// Identical data will be saved as one copy and return the same tag.
- /// Every data has a ref count. When data is saved, ref count increase.
- /// When data is removed, ref count decease. If ref count is decreased
+ /// Every data has a ref count. When data is retained, ref count increase.
+ /// When data is freed, ref count decease. If ref count is decreased
/// to 0, the data entry will be destroyed and no longer occupy space.
- ///
- /// Type is just an attached attribute for convenience and not participate
- /// in identity verification. This should be only used to save blobs but not
- /// strings. It will be rare for identity blob with different type, I think.
/// </remarks>
public interface IDataManager
{
@@ -40,11 +22,9 @@ namespace Timeline.Services /// increases its ref count and returns a tag to the entry.
/// </summary>
/// <param name="data">The data. Can't be null.</param>
- /// <param name="type">The type of the data. Can't be null.</param>
/// <returns>The tag of the created entry.</returns>
- /// <exception cref="ArgumentNullException">Thrown when <paramref name="data"/> or <paramref name="type"/> is null.</exception>
- /// <exception cref="InvalidOperationException">Thrown when a saved copy of data already exists but type is different.</exception>
- public Task<string> RetainEntry(byte[] data, string type);
+ /// <exception cref="ArgumentNullException">Thrown when <paramref name="data"/> is null.</exception>
+ public Task<string> RetainEntry(byte[] data);
/// <summary>
/// Decrease the the ref count of the entry.
@@ -61,19 +41,83 @@ namespace Timeline.Services /// Retrieve the entry with given tag.
/// </summary>
/// <param name="tag">The tag of the entry.</param>
- /// <returns>The entry.</returns>
+ /// <returns>The data of the entry.</returns>
/// <exception cref="ArgumentNullException">Thrown when <paramref name="tag"/> is null.</exception>
/// <exception cref="InvalidOperationException">Thrown when entry with given tag does not exist.</exception>
- public Task<DataEntry> GetEntry(string tag);
-
- /// <summary>
- /// Retrieve info of the entry with given tag.
- /// </summary>
- /// <param name="tag">The tag of the entry.</param>
- /// <returns>The entry info.</returns>
- /// <exception cref="ArgumentNullException">Thrown when <paramref name="tag"/> is null.</exception>
- /// <exception cref="InvalidOperationException">Thrown when entry with given tag does not exist.</exception>
- public Task<DataInfo> GetEntryInfo(string tag);
+ public Task<byte[]> GetEntry(string tag);
}
+ public class DataManager : IDataManager
+ {
+ private readonly DatabaseContext _database;
+ private readonly IETagGenerator _eTagGenerator;
+
+ public DataManager(DatabaseContext database, IETagGenerator eTagGenerator)
+ {
+ _database = database;
+ _eTagGenerator = eTagGenerator;
+ }
+
+ public async Task<string> RetainEntry(byte[] data)
+ {
+ if (data == null)
+ throw new ArgumentNullException(nameof(data));
+
+ var tag = await _eTagGenerator.Generate(data);
+
+ var entity = await _database.Data.Where(d => d.Tag == tag).SingleOrDefaultAsync();
+
+ if (entity == null)
+ {
+ entity = new DataEntity
+ {
+ Tag = tag,
+ Data = data,
+ Ref = 1
+ };
+ _database.Data.Add(entity);
+ await _database.SaveChangesAsync();
+ }
+ else
+ {
+ entity.Ref += 1;
+ await _database.SaveChangesAsync();
+ }
+ return tag;
+ }
+
+ public async Task FreeEntry(string tag)
+ {
+ if (tag == null)
+ throw new ArgumentNullException(nameof(tag));
+
+ var entity = await _database.Data.Where(d => d.Tag == tag).SingleOrDefaultAsync();
+
+ if (entity != null)
+ {
+ if (entity.Ref == 1)
+ {
+ _database.Data.Remove(entity);
+ }
+ else
+ {
+ entity.Ref -= 1;
+ }
+ await _database.SaveChangesAsync();
+ }
+ }
+
+ public async Task<byte[]> GetEntry(string tag)
+ {
+ if (tag == null)
+ throw new ArgumentNullException(nameof(tag));
+
+ var entity = await _database.Data.Where(d => d.Tag == tag).Select(d => new { d.Data }).SingleOrDefaultAsync();
+
+ if (entity == null)
+ throw new InvalidOperationException("Entry with given tag does not exist.");
+
+ return entity.Data;
+ }
+ }
}
|