Query plan execution now works, for the most part

src/databasestorage.rs

@@ -2,7 +2,7 @@ use databaseinfo::DatabaseInfo;
 
 pub trait DatabaseStorage {
     type Info: DatabaseInfo;
-    type ScanTableRowIterator: Iterator<Item=Box<[<Self::Info as DatabaseInfo>::ColumnValue]>>;
 
-    fn scan_table(&self, table: &<Self::Info as DatabaseInfo>::Table) -> Self::ScanTableRowIterator;
+    fn scan_table<'a>(&'a self, table: &'a <Self::Info as DatabaseInfo>::Table)
+    -> Box<Iterator<Item=Box<[<Self::Info as DatabaseInfo>::ColumnValue]>> + 'a>;
 }

src/lib.rs

@@ -1,25 +1,27 @@
-#![feature(core, old_io, old_path, os, collections, unicode)]
+#![feature(core, old_io, collections)]
 #![allow(unused_variables, dead_code)]
 
 #[macro_use]
 extern crate log;
 
-pub mod btree;
-pub mod pager;
-pub mod pagermemory;
-pub mod pagerstream;
+// pub mod btree;
+// pub mod pager;
+// pub mod pagermemory;
+// pub mod pagerstream;
 pub mod sqlsyntax;
 pub mod tempdb;
 
 mod byteutils;
+mod columnvalueops;
 mod databaseinfo;
+mod databasestorage;
 mod identifier;
 mod queryplan;
 mod types;
 
-pub use self::pager::Pager;
-pub use self::pagermemory::PagerMemory;
-pub use self::pagerstream::PagerStream;
+// pub use self::pager::Pager;
+// pub use self::pagermemory::PagerMemory;
+// pub use self::pagerstream::PagerStream;
 
 pub enum SQLError {
 }

src/queryplan/execute.rs

@@ -1,7 +1,7 @@
 use columnvalueops::ColumnValueOps;
 use databaseinfo::DatabaseInfo;
 use databasestorage::DatabaseStorage;
-use super::sexpression::SExpression;
+use super::sexpression::{BinaryOp, SExpression};
 
 struct Source<'a, ColumnValue: Sized + 'static> {
     parent: Option<&'a Source<'a, ColumnValue>>,
@@ -41,17 +41,17 @@ where <Storage::Info as DatabaseInfo>::Table: 'a
         }
     }
 
-    pub fn execute_query_plan<'b, R>(&self, expr: &SExpression<'a, Storage::Info>, result_cb: R)
+    pub fn execute_query_plan<'b, 'c>(&self, expr: &SExpression<'a, Storage::Info>,
+    result_cb: &'c mut FnMut(&[<Storage::Info as DatabaseInfo>::ColumnValue]) -> Result<(), ()>)
     -> Result<(), ()>
-    where R: Fn(&[<Storage::Info as DatabaseInfo>::ColumnValue]) -> Result<(), ()>
     {
-        self.execute(expr, &result_cb, None)
+        self.execute(expr, result_cb, None)
     }
 
-    fn execute<'b, 'c, R>(&self, expr: &SExpression<'a, Storage::Info>, result_cb: &'c R,
+    fn execute<'b, 'c>(&self, expr: &SExpression<'a, Storage::Info>,
+        result_cb: &'c mut FnMut(&[<Storage::Info as DatabaseInfo>::ColumnValue]) -> Result<(), ()>,
         source: Option<&Source<'b, <Storage::Info as DatabaseInfo>::ColumnValue>>)
     -> Result<(), ()>
-    where R: Fn(&[<Storage::Info as DatabaseInfo>::ColumnValue]) -> Result<(), ()>
     {
         match expr {
             &SExpression::Scan { table, source_id, ref yield_fn } => {
@@ -68,7 +68,7 @@ where <Storage::Info as DatabaseInfo>::Table: 'a
                 Ok(())
             },
             &SExpression::Map { source_id, ref yield_in_fn, ref yield_out_fn } => {
-                self.execute(yield_in_fn, &|row| {
+                self.execute(yield_in_fn, &mut |row| {
                     let new_source = Source {
                         parent: source,
                         source_id: source_id,
@@ -122,11 +122,44 @@ where <Storage::Info as DatabaseInfo>::Table: 'a
                 let r = try!(self.resolve_value(rhs, source));
 
                 Ok(match op {
-                    // Equal => l.equal(&r),
-                    // NotEqual => l.not_equal(&r),
+                    BinaryOp::Equal => l.equals(&r),
+                    BinaryOp::NotEqual => l.not_equals(&r),
+                    BinaryOp::And => l.and(&r),
+                    BinaryOp::Or => l.or(&r),
+                    BinaryOp::Concatenate => l.concat(&r),
                     _ => unimplemented!()
                 })
             },
+            &SExpression::Map { source_id, ref yield_in_fn, ref yield_out_fn } => {
+                trace!("resolve_value; map {}", source_id);
+
+                // yield_in_fn is expected to yield exactly one row
+                // yield_out_fn is expected to return a single resolved value
+                let mut r = None;
+                let mut row_count = 0;
+
+                try!(self.execute(yield_in_fn, &mut |row| {
+                    if row_count == 0 {
+                        r = Some(row.to_vec());
+                    }
+                    row_count += 1;
+                    Ok(())
+                }, source));
+
+                if row_count == 1 {
+                    let row = r.unwrap();
+
+                    let new_source = Source {
+                        parent: source,
+                        source_id: source_id,
+                        row: &row
+                    };
+
+                    self.resolve_value(yield_out_fn, Some(&new_source))
+                } else {
+                    Err(())
+                }
+            },
             _ => Err(())
         }
     }

src/tempdb/mod.rs

@@ -6,7 +6,9 @@
 use std::borrow::Cow;
 use std::collections::BTreeSet;
 
+use columnvalueops::ColumnValueOps;
 use databaseinfo::{DatabaseInfo, TableInfo, ColumnInfo};
+use databasestorage::DatabaseStorage;
 use identifier::Identifier;
 use types::{DbType, Variant};
 use sqlsyntax::ast;
@@ -39,6 +41,60 @@ impl DatabaseInfo for TempDb {
     }
 }
 
+impl DatabaseStorage for TempDb {
+    type Info = TempDb;
+
+    fn scan_table<'a>(&'a self, table: &'a Table)
+    -> Box<Iterator<Item=Box<[Variant]>> + 'a>
+    {
+        let columns: &'a [self::table::Column] = &table.columns;
+
+        Box::new(table.rowid_index.iter().map(move |key_v| {
+            use byteutils;
+            use std::borrow::IntoCow;
+
+            let raw_key: &[u8] = &key_v;
+            trace!("KEY: {:?}", raw_key);
+
+            let variable_column_count = columns.iter().filter(|column| {
+                column.dbtype.is_variable_length()
+            }).count();
+
+            let variable_lengths: Vec<_> = (0..variable_column_count).map(|i| {
+                let o = raw_key.len() - (variable_column_count + i) * 8;
+                byteutils::read_udbinteger(&raw_key[o..o+8])
+            }).collect();
+
+            trace!("variable lengths: {:?}", variable_lengths);
+
+            let _rowid: u64 = byteutils::read_udbinteger(&raw_key[0..8]);
+
+            let mut variable_length_offset = 0;
+            let mut key_offset = 8;
+
+            let v: Vec<_> = table.columns.iter().map(|column| {
+                let size = match column.dbtype.get_fixed_length() {
+                    Some(l) => l as usize,
+                    None => {
+                        let l = variable_lengths[variable_length_offset];
+                        variable_length_offset += 1;
+                        l as usize
+                    }
+                };
+
+                let bytes = &raw_key[key_offset..key_offset + size];
+
+                trace!("from bytes: {:?}, {:?}", column.dbtype, bytes);
+                let value = ColumnValueOps::from_bytes(column.dbtype, bytes.into_cow()).unwrap();
+                key_offset += size;
+                value
+            }).collect();
+
+            v.into_boxed_slice()
+        }))
+    }
+}
+
 impl TempDb {
     pub fn new() -> TempDb {
         TempDb {
@@ -163,12 +219,19 @@ impl TempDb {
     }
 
     fn select(&self, stmt: ast::SelectStatement) -> ExecuteStatementResult {
-        use queryplan::QueryPlan;
+        use queryplan::{ExecuteQueryPlan, QueryPlan};
 
         let plan = try!(QueryPlan::compile_select(self, stmt).map_err(|e| format!("{}", e)));
-
         debug!("{}", plan);
 
+        let execute = ExecuteQueryPlan::new(self);
+        let result = execute.execute_query_plan(&plan.expr, &mut |rows| {
+            debug!("ROW: {:?}", rows);
+            Ok(())
+        });
+        
+        trace!("{:?}", result);
+
         unimplemented!()
     }
 
@@ -203,7 +266,6 @@ impl TempDb {
 
 fn ast_expression_to_data(expr: &ast::Expression, column_type: DbType, buf: &mut Vec<u8>) {
     use sqlsyntax::ast::Expression::*;
-    use columnvalueops::ColumnValueOps;
     use std::borrow::IntoCow;
 
     let value: Variant = match expr {

src/types/mod.rs

@@ -97,14 +97,21 @@ impl DbType {
         }
     }
 
-    pub fn is_variable_length(&self) -> bool {
+    pub fn get_fixed_length(&self) -> Option<u64> {
         match self {
-            &DbType::Null => false,
-            &DbType::ByteDynamic => true,
-            &DbType::ByteFixed(_) => false,
-            &DbType::Integer {..} => false,
-            &DbType::F64 => false,
-            &DbType::String => true
+            &DbType::Null => Some(0),
+            &DbType::ByteDynamic => None,
+            &DbType::ByteFixed(n) => Some(n),
+            &DbType::Integer { bytes, ..} => Some(bytes as u64),
+            &DbType::F64 => Some(8),
+            &DbType::String => None
+        }
+    }
+
+    pub fn is_variable_length(&self) -> bool {
+        match self.get_fixed_length() {
+            Some(_) => false,
+            None => true
         }
     }
 }

src/types/variant.rs

@@ -27,6 +27,12 @@ impl fmt::Display for Variant {
     }
 }
 
+impl fmt::Debug for Variant {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        write!(f, "{}", self)
+    }
+}
+
 fn from_bool(value: bool) -> Variant {
     Variant::UnsignedInteger(if value { 1 } else { 0 })
 }