working table

.vscode/launch.json

@@ -0,0 +1,7 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": []
+}

Cargo.lock

@@ -153,6 +153,8 @@ version = "0.1.0"
 dependencies = [
  "bson",
  "serde",
+ "serde_json",
+ "uuid",
 ]
 
 [[package]]

Cargo.toml

@@ -8,3 +8,5 @@ edition = "2021"
 [dependencies]
 bson = "2.10.0"
 serde = "1.0.197"
+serde_json = "1.0.115"
+uuid = "1.8.0"

src/collection.rs

@@ -15,8 +15,10 @@ impl<T> Collection<T>{
     fn get(&self) -> Option<&T>{
         self.entries.get(0)
     }
-    fn new(&mut self, entries: Vec<T>){
-        self.entries = entries;
+    fn new( entries: Vec<T>) -> Collection<T>{
+        Collection{
+            entries:entries
+        }
     }
 }
 
@@ -39,17 +41,17 @@ impl<T> Collection<T>
 where
 T: DeserializeOwned
 {
-    pub fn load(&mut self, mut file: File) -> Result<(), Box<dyn Error>>{
+    pub fn load(mut file: File) -> Result<Collection<T>, Box<dyn Error>>{
         let n = file.metadata()?.len();
         let mut reader = BufReader::new(file);
         let mut current_position = reader.stream_position()?;
+        let mut entries = Vec::new();
         while current_position < n{
             let d = Document::from_reader(&mut reader)?;
             let h: T = bson::from_document(d)?;
-            self.entries.push(h);
+            entries.push(h);
             current_position = reader.stream_position()?;
         }
-        Ok(())
-
+        Ok(Collection::new( entries))
     }
 }

src/main.rs

@@ -1,8 +1,8 @@
 use std::fs::File;
 
+use metalize::table::Table;
 use serde::{Deserialize, Serialize};
-
-mod collection;
+use metalize::collection::Collection;
 
 #[derive(Serialize, Deserialize)]
 struct Potato {
@@ -10,17 +10,19 @@ struct Potato {
 }
 
 fn main() {
-    // let mut peeps: collection::Collection<Potato> = collection::Collection{entries: Vec::new()};
+    // let mut peeps: Collection<Potato> = Collection{entries: Vec::new()};
 
     // peeps.entries.push(Potato{bob:12.0});
     // peeps.entries.push(Potato{bob:42.0});
-    // let mut file = File::create("test.bson").unwrap();
-    // peeps.save(file).unwrap();
+    
 
-    let mut pops: collection::Collection<Potato> = collection::Collection { entries: Vec::new() };
+    // let mut table = Table::init().unwrap();
 
-    let mut file = File::open("test.bson").unwrap();
-    pops.load(file).unwrap();
+    // table.insert(peeps).unwrap();
+
+    let mut table = Table::init().unwrap();
+
+    let mut peeps: Collection<Potato> = table.get(1).unwrap();
 
     println!("blah");
 }

src/table.rs

@@ -1,35 +1,81 @@
-use std::fs::File;
-use serde::{Serialize};
+use std::{fs::File, io::{Seek, BufReader}};
+use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::error::Error;
+use uuid::Uuid;
+use std::path::Path;
+use serde_json;
+
 
 use crate::collection::Collection;
 
+#[derive(Serialize, Deserialize)]
 struct TableRow {
-    id: u32,
-    name: String,
-    num_entries: u32,
+    id: usize,
+    name: Uuid,
+    num_entries: usize,
     path: String
 }
 
 impl TableRow
 {
-    fn new<T:Serialize>(&mut self, id : u32, name: String, entry: Collection<T>) -> Result<(), Box<dyn Error>>{
-        self.id = id;
-        self.name = name.clone();
-        self.num_entries = u32::try_from(entry.entries.len()).unwrap();
-        self.path = format!("{}.bson",name.clone());
-        let mut file = File::create(self.path.clone()).unwrap();
+    fn new<T:Serialize>(id: usize, name: Uuid, entry: Collection<T>) -> Result<TableRow, Box<dyn Error>>{
+        let path = format!("{}.bson", name);
+        let mut file = File::create(&path)?;
         entry.save(file)?;
-        Table::insert(self);
-        Ok(())
+        Ok(
+            TableRow { id: id, name: name, num_entries: entry.entries.len(), path: path  }
+        )
     }
 }
 
-mod Table{
-    use super::TableRow;
+pub struct Table{
+    rows: Vec<TableRow>
+}
 
+impl Table {
 
-    pub fn insert(row :&mut TableRow){
-        
+    fn new() -> Table{
+        Table{ rows:Vec::new()}
+    }
+
+    pub fn init() -> Result<Table, Box<dyn Error>>{
+        let mut table = Table::new();
+
+        // check for existing table entries
+        let path = Path::new("metalize.table");
+        if path.exists(){
+            let file = File::open(path)?;
+            let n = file.metadata()?.len();
+            let mut file = BufReader::new(file);
+            while file.stream_position()? < n {
+                table.rows.push(serde_json::from_reader(&mut file)?);
+            }
+        }
+        Ok(table)
+    }
+
+    pub fn insert<T:Serialize>(&mut self, entry: Collection<T>) -> Result<(), Box<dyn Error>> { 
+        let table_row = TableRow::new(
+            self.rows.len()+1,
+            Uuid::new_v4(),
+            entry
+        )?;
+        let path = Path::new("metalize.table");
+
+        let y = if path.exists() {
+            File::open(path)?
+        } else {
+            File::create(path)?
+        };
+        let x = serde_json::to_value(&table_row)?;
+        serde_json::to_writer(&y, &x)?;
+        self.rows.push(table_row);
+        Ok(())
+    }
+
+    pub fn get<T:DeserializeOwned>(&self, id: usize)-> Result<Collection<T>, Box<dyn Error>>{
+        let table_row = self.rows.get(id-1).expect("Could not access that id.");
+        let mut file = File::open(&table_row.path)?;
+        Collection::load(file)
     }
 }