69 lines
2.3 KiB
Rust
69 lines
2.3 KiB
Rust
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use crate::proc::Processor;
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use crate::proc::range::ProcessorRange;
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#[derive(Copy, Clone)]
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pub struct Checkpoint {
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read_next: usize,
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write_next: usize,
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}
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impl Checkpoint {
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pub fn get_written_range_since(&self, amount: usize) -> ProcessorRange {
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ProcessorRange {
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start: self.write_next,
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end: self.write_next + amount,
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}
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}
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pub fn new(proc: &Processor) -> Checkpoint {
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Checkpoint {
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read_next: proc.read_next,
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write_next: proc.write_next,
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}
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}
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pub fn last_written(&self, proc: &mut Processor) -> Option<u8> {
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if proc.write_next <= self.write_next {
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None
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} else {
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Some(proc.code[proc.write_next - 1])
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}
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}
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/// Write characters skipped from source since self. Must not have written anything since self.
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pub fn write_skipped(&mut self, proc: &mut Processor) -> () {
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// Make sure that nothing has been written since checkpoint (which would be lost).
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debug_assert_eq!(proc.write_next, self.write_next);
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// Get src code from checkpoint until last consumed character (inclusive).
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let src_start = self.read_next;
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let src_end = proc.read_next;
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proc.code.copy_within(src_start..src_end, self.write_next);
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proc.write_next += src_end - src_start;
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}
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/// Discard characters written since checkpoint but keep source position.
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pub fn erase_written(&self, proc: &mut Processor) -> () {
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proc.write_next = self.write_next;
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}
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/// Get consumed characters since checkpoint as range.
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pub fn consumed_range(&self, proc: &mut Processor) -> ProcessorRange {
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ProcessorRange { start: self.read_next, end: proc.read_next }
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}
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/// Get written characters since checkpoint as range.
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pub fn written_range(&self, proc: &mut Processor) -> ProcessorRange {
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ProcessorRange { start: self.write_next, end: proc.write_next }
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}
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/// Get amount of source characters consumed since self.
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pub fn consumed_count(&self, proc: &mut Processor) -> usize {
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proc.read_next - self.read_next
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}
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/// Get amount of output characters written since self.
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pub fn written_count(&self, proc: &mut Processor) -> usize {
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proc.write_next - self.write_next
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}
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}
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