manipulate-linear-memory

Define & Run Host Function

This example demonstrates how to manipulate linear memory.

Now let's build and run this example.

• Install rustup and Rust

  Go to the official Rust webpage and follow the instructions to install rustup and Rust.

  It is recommended to use Rust 1.71 or above in the stable channel.

  Then, add wasm32-wasi target to the Rustup toolchain:

  rustup target add wasm32-wasi

• Install WasmEdge Runtime

  Refer to the Quick Install section of WasmEdge Runtime Book to install WasmEdge Runtime. Or, use the following command directly

  # NOTICE that the installation script needs `sudo` access
  
  # install wasmedge to the directory /usr/local/
  curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash -s -- -v 0.14.0
  source $HOME/.wasmedge/env

  For users in China mainland (中国大陆地区), try the following command to install WasmEdge Runtime if failed to run the command above

  # NOTICE that the installation script needs `sudo` access
  
  bash install_zh.sh -v 0.14.0
  source $HOME/.wasmedge/env 

• Download example

  git clone git@github.com:second-state/wasmedge-rustsdk-examples.git
  cd wasmedge-rustsdk-examples/manipulate-linear-memory

• Build & run

  cargo run

  If the command runs successfully, then the following result is printed out on the screen:

  The memory size (in pages): 1
  The data size (in bytes): 65536
  The memory size (in pages) after growing memory additional 2 pages: 3
  The data size (in bytes) after growing memory additional 2 pages: 196608
  Set 0xFEFEFFE at the memory address 0x2220
  Retrieve the value at the memory address 0x2220: 0xFEFEFFE
  Set 0xFEA09 at the memory address 0x1FFFC
  Retrieve the value at the memory address 0x1FFFC: 0xFEA09