simplified and removed getters

src/builder.rs

@@ -21,7 +21,7 @@ impl Builder {
         }
     }
 
-    pub fn add_record(&mut self, record: Record) {
+    pub fn add_record(&mut self, mut record: Record) {
         if self.current_page_is_full(&record) {
             self.finish_current_page();
             self.leaf_pages.push(mem::replace(&mut self.current_page, Page::new_leaf()));
@@ -29,8 +29,9 @@ impl Builder {
         }
 
         self.current_page.key = record.rowid; //clone?
-        self.current_page.put_vec_u8_bw(record.to_bytes());
+        let bytes: Vec<u8> = record.into();
-        self.current_page.put_u16(self.current_page.get_bw_position() as u16);
+        self.current_page.put_bytes_bw(&bytes);
+        self.current_page.put_u16(self.current_page.bw_position as u16);
         self.n_records_on_current_page += 1;
     }
 
@@ -39,26 +40,26 @@ impl Builder {
     }
 
     pub fn build(mut self) -> Database {
-        self.current_page.set_fw_position(page::POSITION_CELL_COUNT);
+        self.current_page.fw_position = page::POSITION_CELL_COUNT;
         self.current_page.put_u16(self.n_records_on_current_page);
 
         if self.n_records_on_current_page > 0 {
-            self.current_page.put_u16(self.current_page.get_bw_position());
+            self.current_page.put_u16(self.current_page.bw_position);
         } else {
-            self.current_page.put_u16(self.current_page.get_bw_position() - 1);
+            self.current_page.put_u16(self.current_page.bw_position - 1);
         }
 
         Database::new(self.schema.unwrap(), self.leaf_pages) //panics is schema is not set
     }
 
     fn current_page_is_full(&self, record: &Record) -> bool {
-        self.current_page.get_bw_position() - record.get_length() <= self.current_page.get_fw_position() + 5
+        self.current_page.bw_position - record.bytes_len() <= self.current_page.fw_position + 5
     }
 
     fn finish_current_page(&mut self) {
-        self.current_page.set_fw_position(page::POSITION_CELL_COUNT);
+        self.current_page.fw_position = page::POSITION_CELL_COUNT;
         self.current_page.put_u16(self.n_records_on_current_page);
-        self.current_page.put_u16(self.current_page.get_bw_position());
+        self.current_page.put_u16(self.current_page.bw_position);
     }
 }
 

src/bytebuffer.rs

@@ -1,163 +0,0 @@
-use byteorder::{BigEndian, ByteOrder};
-
-/// bytebuffer that supports forward and backward writing (this is not endianness)
-/// Reason: SQLite pages are written in 2 directions: from the front for the cell-pointers and from the back for the cells
-/// - fixed size
-/// - big endian only
-pub struct ByteBuffer {
-    pub data: Vec<u8>,
-    pub fw_position: u16,
-    pub bw_position: u16,
-}
-
-impl ByteBuffer {
-    pub fn new(size: u16) -> Self {
-        Self {
-            data: vec![0; size as usize],
-            fw_position: 0,
-            bw_position: size,
-        }
-    }
-
-    /// forward put unsigned byte array
-    pub fn put_bytes(&mut self, bytes: &[u8]) {
-        for v in bytes {
-            self.data[self.fw_position as usize] = *v;
-            self.fw_position += 1;
-        }
-    }
-
-    /// backward put unsigned byte array
-    pub fn put_bytes_bw(&mut self, bytes: &[u8]) {
-        self.bw_position -= bytes.len() as u16;
-        for v in bytes {
-            self.data[self.bw_position as usize] = *v;
-            self.bw_position += 1;
-        }
-    }
-
-    /// forward put unsigned byte
-    pub fn put_u8(&mut self, byte: u8) {
-        self.put_bytes(&[byte]);
-    }
-
-    /// backward put unsigned byte
-    pub fn put_u8_bw(&mut self, byte: u8) {
-        self.put_bytes_bw(&[byte]);
-    }
-
-    /// forward put unsigned 16bit integer
-    pub fn put_u16(&mut self, val: u16) {
-        let mut buf = [0; 2];
-        BigEndian::write_u16(&mut buf, val);
-        self.put_bytes(&buf);
-    }
-
-    /// backward put unsigned 16bit integer
-    pub fn put_u16_bw(&mut self, val: u16) {
-        let mut buf = [0; 2];
-        BigEndian::write_u16(&mut buf, val);
-        self.put_bytes_bw(&buf);
-    }
-
-    /// forward put unsigned 16bit integer
-    pub fn put_u32(&mut self, val: u32) {
-        let mut buf = [0; 4];
-        BigEndian::write_u32(&mut buf, val);
-        self.put_bytes(&buf);
-    }
-
-    /// backward put unsigned 32bit integer
-    pub fn put_u32_bw(&mut self, val: u32) {
-        let mut buf = [0; 4];
-        BigEndian::write_u32(&mut buf, val);
-        self.put_bytes_bw(&buf);
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_u8() {
-        let mut b = ByteBuffer::new(1);
-        b.put_u8(64_u8);
-        assert_eq!(b.data[0], 64);
-    }
-
-    #[test]
-    fn test_u8a() {
-        let mut b = ByteBuffer::new(2);
-        b.put_bytes(&[1, 2]);
-        assert_eq!(b.data[0], 1);
-        assert_eq!(b.data[1], 2);
-    }
-
-    #[test]
-    fn test_u16() {
-        let mut b = ByteBuffer::new(2);
-        b.put_u16(4096);
-        assert_eq!(b.data[0], 16);
-        assert_eq!(b.data[1], 0);
-    }
-
-    #[test]
-    fn test_u32() {
-        let mut b = ByteBuffer::new(4);
-        b.put_u32(0xFFFFFFFF);
-        assert_eq!(b.data[0], 0xFF);
-        assert_eq!(b.data[1], 0xFF);
-        assert_eq!(b.data[2], 0xFF);
-        assert_eq!(b.data[3], 0xFF);
-    }
-
-    #[test]
-    fn test_u16_position() {
-        let mut b = ByteBuffer::new(4);
-        b.fw_position = 2;
-        b.put_u16(4096);
-        assert_eq!(b.data[0], 0);
-        assert_eq!(b.data[1], 0);
-        assert_eq!(b.data[2], 16);
-        assert_eq!(b.data[3], 0);
-    }
-
-    #[test]
-    fn test_u16_backwards() {
-        let mut b = ByteBuffer::new(4);
-        b.put_u16_bw(0x1000);
-        assert_eq!(b.data[0], 0);
-        assert_eq!(b.data[1], 0);
-        assert_eq!(b.data[2], 0x10);
-        assert_eq!(b.data[3], 0x00);
-    }
-
-    #[test]
-    fn test_u16_2_directions() {
-        let mut b = ByteBuffer::new(5);
-        b.put_u16(0x1001);
-        b.put_u16_bw(0x1000);
-        assert_eq!(b.data[0], 0x10);
-        assert_eq!(b.data[1], 0x01);
-        assert_eq!(b.data[2], 0); // decimal suggests this value has not been written
-        assert_eq!(b.data[3], 0x10);
-        assert_eq!(b.data[4], 0x00);
-    }
-
-    #[test]
-    fn test_u32_2_directions() {
-        let mut b = ByteBuffer::new(9);
-        b.put_u32(0x1001);
-        b.put_u32_bw(0x1002);
-        assert_eq!(b.data[0], 0x00);
-        assert_eq!(b.data[1], 0x00);
-        assert_eq!(b.data[2], 0x10);
-        assert_eq!(b.data[3], 0x01);
-        assert_eq!(b.data[4], 0);
-        assert_eq!(b.data[5], 0x00);
-        assert_eq!(b.data[6], 0x00);
-        assert_eq!(b.data[7], 0x10);
-        assert_eq!(b.data[8], 0x02);
-    }
-}

src/database.rs

@@ -1,3 +1,7 @@
+use std::io::{BufWriter, Write};
+use std::mem;
+use crate::varint;
+use crate::page;
 use crate::page::Page;
 
 pub struct Database {
@@ -16,9 +20,66 @@ impl Database {
 
 pub struct SchemaRecord {}
 
+pub fn write<W: Write>(database: Database, writer: BufWriter<W>) {
+    let mut current_top_layer = database.leaf_pages;
+    let mut n_pages = current_top_layer.len();
+    while current_top_layer.len() > 1 { // interior page needed?
+        current_top_layer = create_interior_pages(current_top_layer);
+        n_pages += current_top_layer.len();
+    }
+
+    let table_root_page = current_top_layer.get(0); //
+    // writeFromStart(writer, createHeaderPage(n_pages + 1)); // 1 for header page
+    //
+    // recursiveAssignPagenumbers(table_root_page); // 3 extra passes... :(
+    // recursiveSetPageReferences(table_root_page); // don't think combining is possible
+    // recursiveWritePages(channel, table_root_page);
+}
+
+fn create_interior_pages(mut child_pages: Vec<Page>) -> Vec<Page> {
+    let mut interior_pages = Vec::new();
+    let mut interior_page = Page::new_interior();
+    interior_page.key = child_pages.iter().map(|p| p.key).max().unwrap();
+    interior_page.fw_position = page::START_OF_INTERIOR_PAGE;
+    let mut page_index = 0;
+    let children_length = child_pages.len();
+    let mut child_count = 0;
+    let mut last_leaf: Page = Page::new_leaf(); // have to assign :(
+    for mut leaf_page in child_pages {
+        if child_count < children_length - 1 {
+            if interior_page.bw_position <= interior_page.fw_position + 15 { // 15 is somewhat arbitrary
+                interior_page.fw_position = page::START_OF_CONTENT_AREA;
+                interior_page.put_u16(interior_page.bw_position);
+                interior_page.put_bytes(&[0, 0, 0, 0, 0]);
+
+                interior_pages.push(mem::replace(&mut interior_page, Page::new_interior()));
+                interior_page.fw_position = page::START_OF_INTERIOR_PAGE;
+            }
+            create_cell(&mut leaf_page);
+            interior_page.add_child(leaf_page);
+            page_index += 1;
+        } else {
+            last_leaf = leaf_page;
+        }
+    }
+
+    interior_page.fw_position = page::START_OF_CONTENT_AREA;
+    interior_page.put_u16(interior_page.bw_position);
+    interior_page.put_bytes(&[0, 0, 0, 0, 0]);
+    interior_page.add_child(last_leaf);
+    interior_pages.push(interior_page);
+    interior_pages
+}
+
+fn create_cell(page: &mut Page) {
+    let mut cell: Vec<u8> = vec![0, 0, 0, 0]; // not an expensive call right?
+    cell.append(&mut varint::write(page.key));
+    page.put_bytes_bw(&cell);
+    page.put_u16(page.bw_position);
+}
 
 fn write_header(mut rootpage: Page, n_pages: u32) {
-    rootpage.put_u8a(&MAGIC_HEADER);
+    rootpage.put_bytes(&MAGIC_HEADER);
     rootpage.put_u16(DEFAULT_PAGE_SIZE);
     rootpage.put_u8(FILE_FORMAT_WRITE_VERSION);
     rootpage.put_u8(FILE_FORMAT_READ_VERSION);
@@ -38,9 +99,9 @@ fn write_header(mut rootpage: Page, n_pages: u32) {
     rootpage.put_u32(USER_VERSION);
     rootpage.put_u32(VACUUM_MODE_OFF);// True (non-zero) for incremental-vacuum mode. False (zero) otherwise.
     rootpage.put_u32(APP_ID);// Application ID
-    rootpage.put_u8a(&FILLER);// Reserved for expansion. Must be zero.
+    rootpage.put_bytes(&FILLER);// Reserved for expansion. Must be zero.
-    rootpage.put_u8a(&VERSION_VALID_FOR);// The version-valid-for number
+    rootpage.put_bytes(&VERSION_VALID_FOR);// The version-valid-for number
-    rootpage.put_u8a(&SQLITE_VERSION);// SQLITE_VERSION_NUMBER
+    rootpage.put_bytes(&SQLITE_VERSION);// SQLITE_VERSION_NUMBER
     rootpage.put_u8(TABLE_LEAF_PAGE); // leaf table b-tree page for schema
     rootpage.put_u16(NO_FREE_BLOCKS); // zero if there are no freeblocks
     rootpage.put_u16(1); // the number of cells on this page

src/lib.rs

@@ -2,7 +2,6 @@
 
 mod page;
 mod database;
-mod bytebuffer;
 mod values;
 mod varint;
 mod record;

src/page.rs

@@ -1,17 +1,22 @@
-use crate::bytebuffer::ByteBuffer;
+use byteorder::{BigEndian, ByteOrder};
 use crate::database;
 
 pub const POSITION_CELL_COUNT: u16 = 3;
-const START_OF_CONTENT_AREA: u32 = 5;
+pub const START_OF_CONTENT_AREA: u16 = 5;
+pub const START_OF_INTERIOR_PAGE: u16 = 12;
 
 pub enum PageType {
     Leaf,
     Interior,
+    Root,
+    Other
 }
 
 /// Represents an SQLite page
 pub struct Page {
-    data: ByteBuffer,
+    pub data: Vec<u8>,
+    pub fw_position: u16,
+    pub bw_position: u16,
     pub key: u64,
     children: Vec<Page>,
     number: u32,
@@ -19,9 +24,11 @@ pub struct Page {
 }
 
 impl Page {
-    pub fn with_capacity(size: u16, page_type: PageType) -> Self {
+    fn with_capacity(size: u16, page_type: PageType) -> Self {
         Self {
-            data: ByteBuffer::new(size as u16),
+            data: vec![0; size as usize],
+            fw_position: 0,
+            bw_position: size,
             key: 0,
             children: Vec::new(),
             number: 0,
@@ -29,6 +36,18 @@ impl Page {
         }
     }
 
+    fn default(size: usize) -> Self{
+        Self {
+            data: vec![0; size],
+            fw_position: 0,
+            bw_position: size as u16,
+            key: 0,
+            children: Vec::new(),
+            number: 0,
+            page_type: PageType::Other,
+        }
+    }
+
     pub fn new_leaf() -> Self {
         let mut page = Page::with_capacity(database::DEFAULT_PAGE_SIZE, PageType::Leaf);
         page.put_u8(database::TABLE_LEAF_PAGE);
@@ -45,47 +64,43 @@ impl Page {
         self.children.push(child);
     }
 
-    pub fn set_fw_position(&mut self, new_position: u16) {
+    pub fn put_bytes(&mut self, bytes: &[u8]) {
-        self.data.fw_position = new_position;
+        for v in bytes {
+            self.data[self.fw_position as usize] = *v;
+            self.fw_position += 1;
+        }
     }
 
-    pub fn get_fw_position(&self) -> u16 {
+    pub fn put_bytes_bw(&mut self, bytes: &[u8]) {
-        self.data.fw_position
+        self.bw_position -= bytes.len() as u16;
+        for v in bytes {
+            self.data[self.bw_position as usize] = *v;
+            self.bw_position += 1;
         }
-    pub fn set_bw_position(&mut self, new_position: u16) {
-        self.data.bw_position = new_position;
-    }
-
-    pub fn get_bw_position(&self) -> u16 {
-        self.data.bw_position
-    }
-
-    pub fn put_u8a(&mut self, value: &[u8]) {
-        self.data.put_bytes(value);
-    }
-
-    pub fn put_u8a_bw(&mut self, value: &[u8]) {
-        self.data.put_bytes_bw(value);
-    }
-
-    pub fn put_vec_u8_bw(&mut self, value: Vec<u8>) {
-        self.data.put_bytes_bw(&value);
     }
 
     pub fn put_u8(&mut self, value: u8) {
-        self.data.put_u8(value);
+        self.put_bytes(&[value]);
     }
 
     pub fn put_u8_bw(&mut self, value: u8) {
-        self.data.put_u8_bw(value);
+        self.put_bytes_bw(&[value]);
     }
 
     pub fn put_u16(&mut self, value: u16) {
-        self.data.put_u16(value);
+        self.put_bytes(&u16_to_bytes(value));
+    }
+
+    pub fn put_u16_bw(&mut self, value: u16) {
+        self.put_bytes_bw(&u16_to_bytes(value));
     }
 
     pub fn put_u32(&mut self, value: u32) {
-        self.data.put_u32(value);
+        self.put_bytes(&u32_to_bytes(value));
+    }
+
+    pub fn put_u32_bw(&mut self, value: u32) {
+        self.put_bytes_bw(&u32_to_bytes(value));
     }
 
     // may panic
@@ -93,3 +108,102 @@ impl Page {
         self.children[self.children.len() - 1].number
     }
 }
+
+fn u16_to_bytes(value: u16) -> [u8; 2] {
+    let mut buf = [0; 2];
+    BigEndian::write_u16(&mut buf, value);
+    buf
+}
+
+fn u32_to_bytes(value: u32) -> [u8; 4] {
+    let mut buf = [0; 4];
+    BigEndian::write_u32(&mut buf, value);
+    buf
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_u8() {
+        let mut b = Page::default(1);
+        b.put_u8(64_u8);
+        assert_eq!(b.data[0], 64);
+    }
+
+    #[test]
+    fn test_u8a() {
+        let mut b = Page::default(2);
+        b.put_bytes(&[1, 2]);
+        assert_eq!(b.data[0], 1);
+        assert_eq!(b.data[1], 2);
+    }
+
+    #[test]
+    fn test_u16() {
+        let mut b = Page::default(2);
+        b.put_u16(4096);
+        assert_eq!(b.data[0], 16);
+        assert_eq!(b.data[1], 0);
+    }
+
+    #[test]
+    fn test_u32() {
+        let mut b = Page::default(4);
+        b.put_u32(0xFFFFFFFF);
+        assert_eq!(b.data[0], 0xFF);
+        assert_eq!(b.data[1], 0xFF);
+        assert_eq!(b.data[2], 0xFF);
+        assert_eq!(b.data[3], 0xFF);
+    }
+
+    #[test]
+    fn test_u16_position() {
+        let mut b = Page::default(4);
+        b.fw_position = 2;
+        b.put_u16(4096);
+        assert_eq!(b.data[0], 0);
+        assert_eq!(b.data[1], 0);
+        assert_eq!(b.data[2], 16);
+        assert_eq!(b.data[3], 0);
+    }
+
+    #[test]
+    fn test_u16_backwards() {
+        let mut b = Page::default(4);
+        b.put_u16_bw(0x1000);
+        assert_eq!(b.data[0], 0);
+        assert_eq!(b.data[1], 0);
+        assert_eq!(b.data[2], 0x10);
+        assert_eq!(b.data[3], 0x00);
+    }
+
+    #[test]
+    fn test_u16_2_directions() {
+        let mut b = Page::default(5);
+        b.put_u16(0x1001);
+        b.put_u16_bw(0x1000);
+        assert_eq!(b.data[0], 0x10);
+        assert_eq!(b.data[1], 0x01);
+        assert_eq!(b.data[2], 0); // decimal suggests this value has not been written
+        assert_eq!(b.data[3], 0x10);
+        assert_eq!(b.data[4], 0x00);
+    }
+
+    #[test]
+    fn test_u32_2_directions() {
+        let mut b = Page::default(9);
+        b.put_u32(0x1001);
+        b.put_u32_bw(0x1002);
+        assert_eq!(b.data[0], 0x00);
+        assert_eq!(b.data[1], 0x00);
+        assert_eq!(b.data[2], 0x10);
+        assert_eq!(b.data[3], 0x01);
+        assert_eq!(b.data[4], 0);
+        assert_eq!(b.data[5], 0x00);
+        assert_eq!(b.data[6], 0x00);
+        assert_eq!(b.data[7], 0x10);
+        assert_eq!(b.data[8], 0x02);
+    }
+}

src/record.rs

@@ -1,4 +1,3 @@
-use crate::bytebuffer::ByteBuffer;
 use crate::values::*;
 use crate::varint;
 
@@ -20,38 +19,42 @@ impl Record {
         self.values.push(value);
     }
 
-    pub fn to_bytes(&self) -> Vec<u8> {
+    /// length of the byte representation
-        let record_length = self.get_length();
+    pub fn bytes_len(&self) -> u16 {
-        let length_bytes = varint::write(record_length as u64);
+        let record_length: u16 = self.values.iter()
-        let rowid_bytes = varint::write(self.rowid);
+            .map(|v| v.len())
+            .sum();
+        record_length
+    }
+}
 
-        let mut buffer = ByteBuffer::new(length_bytes.len() as u16 + rowid_bytes.len() as u16 + record_length);
+impl Into<Vec<u8>> for Record{
-        buffer.put_bytes(&length_bytes);
+    fn into(mut self) -> Vec<u8> {
-        buffer.put_bytes(&rowid_bytes);
+        let record_length = self.bytes_len();
+        let mut length_bytes = varint::write(record_length as u64);
+        let mut rowid_bytes = varint::write(self.rowid);
+
+        // let mut buffer = Vec::with_capacity(length_bytes.len() + rowid_bytes.len() + record_length);
+        let mut buffer = Vec::new();
+        buffer.append(&mut length_bytes);
+        buffer.append(&mut rowid_bytes);
 
         // 'The initial portion of the payload that does not spill to overflow pages.'
         let length_of_encoded_column_types: usize = self.values.iter()
             .map(|v| v.datatype.len())
             .sum();
-        buffer.put_bytes(&varint::write((length_of_encoded_column_types + 1) as u64));
+        buffer.append(&mut varint::write((length_of_encoded_column_types + 1) as u64));
 
         //write all types
-        for v in self.values.iter() {
+        for v in self.values.iter_mut() {
-            buffer.put_bytes(&v.datatype)
+            buffer.append(&mut v.datatype)
         }
 
         //  write all values
-        for v in self.values.iter() {
+        for v in self.values.iter_mut() {
-            buffer.put_bytes(&v.data) //copies individual bytes into a buffer...should I avoid copying?
+            buffer.append(&mut v.data)
         }
-        buffer.data
+        buffer
-    }
-
-    pub fn get_length(&self) -> u16 {
-        let record_length: u16 = self.values.iter()
-            .map(|v| v.get_length())
-            .sum();
-        record_length
     }
 }