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Fix memory max pages (#33) 

* Fix memory max pages

* Get rid of calculate_memory_size.
This commit is contained in:
Sergey Pepyakin 2018-02-02 00:44:06 +03:00 committed by Nikolay Volf
parent fa82dee676
commit 106ac7afdb
1 changed files with 47 additions and 17 deletions
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64
src/memory.rs
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@ -111,14 +111,18 @@ impl MemoryInstance {
fn new(limits: ResizableLimits) -> Result<Self, Error> {
check_limits(&limits)?;
let maximum_size = match limits.maximum() {
Some(maximum_pages) if maximum_pages > LINEAR_MEMORY_MAX_PAGES =>
return Err(Error::Memory(format!("maximum memory size must be at most {} pages", LINEAR_MEMORY_MAX_PAGES))),
Some(maximum_pages) => maximum_pages.saturating_mul(LINEAR_MEMORY_PAGE_SIZE),
None => u32::MAX,
};
let initial_size = calculate_memory_size(0, limits.initial(), maximum_size)
.ok_or_else(|| Error::Memory(format!("initial memory size must be at most {} pages", LINEAR_MEMORY_MAX_PAGES)))?;
let initial_pages = limits.initial();
let maximum_pages = limits.maximum().unwrap_or(LINEAR_MEMORY_MAX_PAGES);
if initial_pages > LINEAR_MEMORY_MAX_PAGES {
return Err(Error::Memory(format!("initial memory size must be at most {} pages", LINEAR_MEMORY_MAX_PAGES)));
}
if maximum_pages > LINEAR_MEMORY_MAX_PAGES {
return Err(Error::Memory(format!("maximum memory size must be at most {} pages", LINEAR_MEMORY_MAX_PAGES)));
}
let maximum_size = maximum_pages.saturating_mul(LINEAR_MEMORY_PAGE_SIZE);
let initial_size = initial_pages.saturating_mul(LINEAR_MEMORY_PAGE_SIZE);
let memory = MemoryInstance {
limits: limits,
@ -274,23 +278,49 @@ impl MemoryInstance {
}
fn calculate_memory_size(old_size: u32, additional_pages: u32, maximum_size: u32) -> Option<u32> {
additional_pages
.checked_mul(LINEAR_MEMORY_PAGE_SIZE)
.and_then(|size| size.checked_add(old_size))
.and_then(|size| if size > maximum_size {
None
} else {
Some(size)
})
let size = additional_pages
.saturating_mul(LINEAR_MEMORY_PAGE_SIZE);
match size.checked_add(old_size) {
Some(size) if size <= maximum_size => Some(size),
_ => None,
}
}
#[cfg(test)]
mod tests {
use super::MemoryInstance;
use super::{MemoryInstance, LINEAR_MEMORY_MAX_PAGES};
use Error;
use parity_wasm::elements::ResizableLimits;
#[test]
fn alloc() {
let fixtures = &[
(0, None, true),
(0, Some(0), true),
(1, None, true),
(1, Some(1), true),
(0, Some(1), true),
(1, Some(0), false),
(0, Some(LINEAR_MEMORY_MAX_PAGES), true),
(LINEAR_MEMORY_MAX_PAGES, Some(LINEAR_MEMORY_MAX_PAGES), true),
(LINEAR_MEMORY_MAX_PAGES, Some(0), false),
(LINEAR_MEMORY_MAX_PAGES, None, true),
];
for &(initial, maybe_max, expected_ok) in fixtures {
let result = MemoryInstance::alloc(initial, maybe_max);
if result.is_ok() != expected_ok {
panic!(
"unexpected error, initial={}, max={:?}, expected={}, result={:?}",
initial,
maybe_max,
expected_ok,
result,
);
}
}
}
fn create_memory(initial_content: &[u8]) -> MemoryInstance {
let mem = MemoryInstance::new(ResizableLimits::new(1, Some(1)))
.expect("MemoryInstance created successfuly");