add meta block: for block height

executor/src/execution.rs

@@ -19,7 +19,7 @@ use crate::explain::{
  explain_type_error,
 };
 use crate::meta::ExecutionMeta;
-use crate::oracles::{oracle_coins_module, time_metadata, coin_balance_metadata};
+use crate::oracles::{oracle_coins_module, time_metadata, coin_balance_metadata, block_metadata};
 use move_vm_runtime::logging::NoContextLog;
 use crate::session::ConstsMap;
 
@@ -176,6 +176,7 @@ pub fn execute_script(
  current_time,
  aborts_with,
  status,
+ block,
  dry_run,
  } = meta;
  if !oracle_prices.is_empty() {
@@ -194,6 +195,11 @@ pub fn execute_script(
  lcs::to_bytes(&current_time).unwrap(),
  );
  }
+ let block_height = block.unwrap_or(100);
+ ds.resources.insert(
+ (std_addr, block_metadata()),
+ lcs::to_bytes(&block_height).unwrap(),
+ );
  for (price_tag, val) in oracle_prices {
  ds.resources
  .insert((std_addr, price_tag), lcs::to_bytes(&val).unwrap());

executor/src/meta.rs

@@ -33,6 +33,7 @@ pub struct ExecutionMeta {
  pub accounts_balance: Vec<(AccountAddress, String, u128)>,
  pub oracle_prices: Vec<(StructTag, u128)>,
  pub current_time: Option<u64>,
+ pub block: Option<u64>,
  pub aborts_with: Option<u64>,
  pub status: Option<u64>,
  pub dry_run: bool,
@@ -86,6 +87,7 @@ impl ExecutionMeta {
  eprintln!("Unknown status code name: {:?}", val);
  }
  }
+ "block" => self.block = Some(val.parse().unwrap()),
  "dry_run" => self.dry_run = val.parse().unwrap(),
  _ => eprintln!("Unimplemented meta key, {:?}", key),
  }

executor/src/oracles.rs

@@ -11,6 +11,8 @@ const ACCOUNT_BALANCE_STRUCT: &str = "Balance";
 const XFI_MODULE: &str = "XFI";
 const XFI_RESOURCE: &str = "T";
 
+const BLOCK_RESOURCE: &str = "BlockMetadata";
+
 /// Currency price.
 #[derive(Debug, PartialEq, Eq)]
 pub struct Price {
@@ -52,6 +54,15 @@ pub fn oracle_metadata(first: &str, second: &str) -> StructTag {
  }
 }
 
+pub fn block_metadata() -> StructTag {
+ StructTag {
+ address: CORE_CODE_ADDRESS,
+ name: Identifier::new(BLOCK_RESOURCE).expect("Valid module name."),
+ module: Identifier::new("Block").expect("Valid module name."),
+ type_params: vec![],
+ }
+}
+
 pub fn time_metadata() -> StructTag {
  StructTag {
  address: CORE_CODE_ADDRESS,

executor/tests/test_executor.rs

@@ -1037,3 +1037,56 @@ script {
  "Expected error: Execution failed with an arithmetic error (i.e., integer overflow/underflow, div/mod by zero, or invalid shift) in script at code offset 2"
  );
 }
+
+#[test]
+fn test_set_block_height() {
+ let _pool = ConstPool::new();
+
+ let text = r"
+/// block: 1024
+script {
+ use 0x1::Block;
+
+ fun success() {
+ assert(Block::get_current_block_height() == 1024, 1);
+ }
+} ";
+
+ execute_script(
+ MoveFile::with_content(script_path(), text),
+ vec![stdlib_mod("block.move")],
+ "libra",
+ "0x3",
+ vec![],
+ )
+ .unwrap()
+ .last()
+ .unwrap()
+ .effects();
+}
+
+#[test]
+fn test_block_height_default_100() {
+ let _pool = ConstPool::new();
+
+ let text = r"
+script {
+ use 0x1::Block;
+
+ fun success() {
+ assert(Block::get_current_block_height() == 100, 1);
+ }
+} ";
+
+ execute_script(
+ MoveFile::with_content(script_path(), text),
+ vec![stdlib_mod("block.move")],
+ "libra",
+ "0x3",
+ vec![],
+ )
+ .unwrap()
+ .last()
+ .unwrap()
+ .effects();
+}

resources/assets/stdlib/block.move

@@ -0,0 +1,15 @@
+address 0x1 {
+
+module Block {
+
+ resource struct BlockMetadata {
+ // height of the current block
+ height: u64,
+ }
+
+ // Get the current block height
+ public fun get_current_block_height(): u64 acquires BlockMetadata {
+ borrow_global<BlockMetadata>(0x1).height
+ }
+}
+}