From 5d4cd0949731ffaf852f97d0ff227cc0f1c0211c Mon Sep 17 00:00:00 2001
From: yukirij <yukirij@yukiri.jp>
Date: Thu, 22 May 2025 22:17:43 -0700
Subject: [PATCH] Start database implementation.

---
 src/database/header.rs | 19 ++++++++++
 src/database/mod.rs    | 82 ++++++++++++++++++++++++++++++++++++++++++
 src/database/page.rs   | 74 ++++++++++++++++++++++++++++++++++++++
 src/database/trie.rs   |  8 +++++
 src/lib.rs             |  1 +
 5 files changed, 184 insertions(+)
 create mode 100644 src/database/header.rs
 create mode 100644 src/database/mod.rs
 create mode 100644 src/database/page.rs
 create mode 100644 src/database/trie.rs

diff --git a/src/database/header.rs b/src/database/header.rs
new file mode 100644
index 0000000..9165be5
--- /dev/null
+++ b/src/database/header.rs
@@ -0,0 +1,19 @@
+pub struct Header {
+    pub depth:u8,
+    pub root:u32,
+}
+impl Header {
+    pub fn serialize(&self) -> [u8;16]
+    {
+        [0; 16]
+    }
+}
+impl Default for Header {
+    fn default() -> Self
+    {
+        Self {
+            depth:1,
+            root:1,
+        }
+    }
+}
diff --git a/src/database/mod.rs b/src/database/mod.rs
new file mode 100644
index 0000000..ca36247
--- /dev/null
+++ b/src/database/mod.rs
@@ -0,0 +1,82 @@
+use tokio::{
+    fs::File,
+    io::{
+        Error, SeekFrom,
+        AsyncWriteExt, AsyncSeekExt
+    },
+};
+use std::collections::BTreeSet;
+
+mod header;
+mod page;
+mod trie;
+
+const PAGE_SIZE :u64 = 4096;
+
+enum Path {
+    Index(usize),
+    Key(&u8),
+}
+
+pub struct Database {
+    file:File,
+    temp:BTreeSet<u64>,
+}
+impl Database {
+    async fn init(&mut self) -> Result<(),Error>
+    {
+        let mut header = header::Header::default();
+        header.depth = 1;
+        header.root = 2;
+
+        let buffered = header.serialize();
+
+        self.file.set_len(PAGE_SIZE * 3).await?;
+
+        self.file.seek(SeekFrom::Start(0)).await?;
+        self.file.write(&buffered).await?;
+
+        self.file.seek(SeekFrom::Start(PAGE_SIZE)).await?;
+        self.file.write(&buffered).await?;
+
+        Ok(())
+    }
+}
+impl From<File> for Database {
+    fn from(value: File) -> Self
+    {
+        Self {
+            file:value,
+            temp:BTreeSet::new(),
+        }
+    }
+}
+
+/* Object
+** Meta [16]
+**  [0:3] Type
+** 
+**  00 Blob
+**    [3:3] Size
+**
+**  01 List
+**    []
+**
+**  10 Trie
+**
+** Addr [48]
+*/
+
+/* Page Table Entry
+**  <>
+*/
+
+/* Allocation Table Entry
+**  <>
+**
+*/
+
+/* Header
+**  <>
+**  
+*/
diff --git a/src/database/page.rs b/src/database/page.rs
new file mode 100644
index 0000000..300e0f9
--- /dev/null
+++ b/src/database/page.rs
@@ -0,0 +1,74 @@
+pub enum Usage {
+    Blob  = 0b00,
+    List  = 0b01,
+    Trie  = 0b10,
+    Table = 0b11,
+}
+
+pub struct Entry {
+    addr:u64,
+    res:u64,
+}
+impl Entry {
+    pub fn new() -> Self
+    {
+        Self {
+            addr:0,
+            res:0,
+        }
+    }
+
+    pub fn blob(address:u64, size:u8) -> Self
+    {
+        let addr = address & ((1 << 48) - 1);
+        let size = (size as u64) << 48;
+        Self {
+            addr: size|addr,
+            res: 0,
+        }
+    }
+
+    pub fn serialize(&self) -> [u8;16]
+    {
+        [
+            (self.addr & 0xFF) as u8,
+            ((self.addr >> 8) & 0xFF) as u8,
+            ((self.addr >> 16) & 0xFF) as u8,
+            ((self.addr >> 24) & 0xFF) as u8,
+            ((self.addr >> 32) & 0xFF) as u8,
+            ((self.addr >> 40) & 0xFF) as u8,
+            ((self.addr >> 48) & 0xFF) as u8,
+            ((self.addr >> 56) & 0xFF) as u8,
+
+            (self.res & 0xFF) as u8,
+            ((self.res >> 8) & 0xFF) as u8,
+            ((self.res >> 16) & 0xFF) as u8,
+            ((self.res >> 24) & 0xFF) as u8,
+            ((self.res >> 32) & 0xFF) as u8,
+            ((self.res >> 40) & 0xFF) as u8,
+            ((self.res >> 48) & 0xFF) as u8,
+            ((self.res >> 56) & 0xFF) as u8,
+        ]
+    }
+
+    pub fn deserialize(&mut self, data:[u8;16])
+    {
+        self.addr = data[0] as u64
+            |(data[1] << 8) as u64
+            |(data[2] << 16) as u64
+            |(data[3] << 24) as u64
+            |(data[4] << 32) as u64
+            |(data[5] << 40) as u64
+            |(data[6] << 48) as u64
+            |(data[7] << 56) as u64;
+
+        self.res = data[8] as u64
+            |(data[9] << 8) as u64
+            |(data[10] << 16) as u64
+            |(data[11] << 24) as u64
+            |(data[12] << 32) as u64
+            |(data[13] << 40) as u64
+            |(data[14] << 48) as u64
+            |(data[15] << 56) as u64;
+    }
+}
diff --git a/src/database/trie.rs b/src/database/trie.rs
new file mode 100644
index 0000000..9355623
--- /dev/null
+++ b/src/database/trie.rs
@@ -0,0 +1,8 @@
+pub struct TrieEntry {
+    meta:u8,
+    bytes:[u8; 11],
+    child:u32,
+    lesser:u32,
+    greater:u32,
+    data:u64,
+}
diff --git a/src/lib.rs b/src/lib.rs
index 372e333..bbd7654 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,3 +2,4 @@
 
 mod blockfile; pub use blockfile::BlockFile;
 mod triefile; pub use triefile::TrieFile;
+mod database; pub use database::Database;