feat: rewriting the gas-estimation to be linear (#37)

Author: YaronWittenstein

Cargo.lock

@@ -10,7 +10,6 @@ publish = false
 [dependencies]
 parity-wasm = "0.40.2"
 log = "0.4"
-wasmparser = "0.39.2"
 
 [dev-dependencies]
 wabt = "0.7.4"

crates/svm-gas/Cargo.toml

@@ -4,10 +4,9 @@ use crate::program::Program;
 use std::collections::HashMap;
 
 use parity_wasm::elements::{ImportCountType, Module};
-use wasmparser::{Operator, Parser, ParserState, WasmDecoder};
 
-#[allow(unused)]
-pub(crate) fn read_program(wasm: &[u8]) -> Program {
+/// Reads wasm input and contruct a `Program` struct
+pub fn read_program(wasm: &[u8]) -> Program {
     let mut functions = HashMap::new();
 
     let module: Module = parity_wasm::deserialize_buffer(wasm).unwrap();
@@ -27,48 +26,3 @@ pub(crate) fn read_program(wasm: &[u8]) -> Program {
         imported_count,
     }
 }
-
-#[allow(unused)]
-pub(crate) fn parse_program(wasm: &[u8]) -> HashMap<FuncIndex, Vec<Operator>> {
-    let mut parser = Parser::new(wasm);
-    let mut function_readers = Vec::new();
-
-    while !(parser.eof()) {
-        match parser.read() {
-            ParserState::BeginFunctionBody { .. } => {
-                while !(parser.eof()) {
-                    let reader = parser.create_binary_reader();
-                    function_readers.push(reader);
-                }
-            }
-            _ => continue,
-        }
-    }
-
-    for (i, reader) in function_readers.iter_mut().enumerate() {
-        while let Ok(ref op) = reader.read_operator() {
-            //
-        }
-    }
-
-    panic!()
-
-    //     let mut functions = HashMap::new();
-    //
-    //     let module: Module = parity_wasm::deserialize_buffer(wasm).unwrap();
-    //
-    //     let code_section = module.code_section().expect("no code section");
-    //     let imported_count = module.import_count(ImportCountType::Function) as u32;
-    //
-    //     for (i, func_body) in code_section.bodies().iter().enumerate() {
-    //         let fn_idx = FuncIndex((i as u32) + imported_count);
-    //         let fn_body = FuncBody(func_body.code().clone());
-    //
-    //         functions.insert(fn_idx, fn_body);
-    //     }
-    //
-    //     Program {
-    //         functions,
-    //         imported_count,
-    //     }
-}