use anyhow::{anyhow, Result}; use rand::prelude::*; use std::collections::VecDeque; use std::fs::OpenOptions; use std::ops::Range; use std::path::Path; use thinp::thin::xml; //------------------------------------------ pub trait XmlGen { fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()>; } pub fn write_xml(path: &Path, g: &mut dyn XmlGen) -> Result<()> { let xml_out = OpenOptions::new() .read(false) .write(true) .create(true) .truncate(true) .open(path)?; let mut w = xml::XmlWriter::new(xml_out); g.generate_xml(&mut w) } fn common_sb(nr_blocks: u64) -> xml::Superblock { xml::Superblock { uuid: "".to_string(), time: 0, transaction: 0, flags: None, version: None, data_block_size: 32, nr_data_blocks: nr_blocks, metadata_snap: None, } } //------------------------------------------ pub struct EmptyPoolS {} impl XmlGen for EmptyPoolS { fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { v.superblock_b(&common_sb(1024))?; v.superblock_e()?; Ok(()) } } //------------------------------------------ pub struct SingleThinS { pub offset: u64, pub len: u64, pub old_nr_data_blocks: u64, pub new_nr_data_blocks: u64, } impl SingleThinS { pub fn new(offset: u64, len: u64, old_nr_data_blocks: u64, new_nr_data_blocks: u64) -> Self { SingleThinS { offset, len, old_nr_data_blocks, new_nr_data_blocks, } } } impl XmlGen for SingleThinS { fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { v.superblock_b(&common_sb(self.old_nr_data_blocks))?; v.device_b(&xml::Device { dev_id: 0, mapped_blocks: self.len, transaction: 0, creation_time: 0, snap_time: 0, })?; v.map(&xml::Map { thin_begin: 0, data_begin: self.offset, time: 0, len: self.len, })?; v.device_e()?; v.superblock_e()?; Ok(()) } } //------------------------------------------ pub struct FragmentedS { pub nr_thins: u32, pub thin_size: u64, pub old_nr_data_blocks: u64, pub new_nr_data_blocks: u64, } impl FragmentedS { pub fn new(nr_thins: u32, thin_size: u64) -> Self { let old_size = (nr_thins as u64) * thin_size; FragmentedS { nr_thins, thin_size, old_nr_data_blocks: (nr_thins as u64) * thin_size, new_nr_data_blocks: old_size * 3 / 4, } } } #[derive(Clone)] struct ThinRun { thin_id: u32, thin_begin: u64, len: u64, } #[derive(Clone, Debug, Copy)] struct MappedRun { thin_id: u32, thin_begin: u64, data_begin: u64, len: u64, } fn mk_runs(thin_id: u32, total_len: u64, run_len: std::ops::Range) -> Vec { let mut runs = Vec::new(); let mut b = 0u64; while b < total_len { let len = u64::min( total_len - b, thread_rng().gen_range(run_len.start, run_len.end), ); runs.push(ThinRun { thin_id: thin_id, thin_begin: b, len, }); b += len; } runs } impl XmlGen for FragmentedS { fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { // Allocate each thin fully, in runs between 1 and 16. let mut runs = Vec::new(); for thin in 0..self.nr_thins { runs.append(&mut mk_runs(thin, self.thin_size, 1..17)); } // Shuffle runs.shuffle(&mut rand::thread_rng()); // map across the data let mut maps = Vec::new(); let mut b = 0; for r in &runs { maps.push(MappedRun { thin_id: r.thin_id, thin_begin: r.thin_begin, data_begin: b, len: r.len, }); b += r.len; } // drop half the mappings, which leaves us free runs let mut dropped = Vec::new(); for i in 0..maps.len() { if i % 2 == 0 { dropped.push(maps[i].clone()); } } // Unshuffle. This isn't strictly necc. but makes the xml // more readable. use std::cmp::Ordering; maps.sort_by(|&l, &r| match l.thin_id.cmp(&r.thin_id) { Ordering::Equal => l.thin_begin.cmp(&r.thin_begin), o => o, }); // write the xml v.superblock_b(&common_sb(self.old_nr_data_blocks))?; for thin in 0..self.nr_thins { v.device_b(&xml::Device { dev_id: thin, mapped_blocks: self.thin_size, transaction: 0, creation_time: 0, snap_time: 0, })?; for m in &dropped { if m.thin_id != thin { continue; } v.map(&xml::Map { thin_begin: m.thin_begin, data_begin: m.data_begin, time: 0, len: m.len, })?; } v.device_e()?; } v.superblock_e()?; Ok(()) } } //------------------------------------------ struct Allocator { runs: VecDeque>, } impl Allocator { fn new_shuffled(total_len: u64, run_len: Range) -> Allocator { let mut runs = Vec::new(); let mut b = 0u64; while b < total_len { let len = u64::min( total_len - b, thread_rng().gen_range(run_len.start, run_len.end), ); runs.push(b..(b + len)); b += len; } runs.shuffle(&mut thread_rng()); let runs: VecDeque> = runs.iter().map(|r| r.clone()).collect(); Allocator { runs } } #[allow(dead_code)] fn is_empty(&self) -> bool { self.runs.is_empty() } fn alloc(&mut self, len: u64) -> Result>> { let mut len = len; let mut runs = Vec::new(); while len > 0 { let r = self.runs.pop_front(); if r.is_none() { return Err(anyhow!("could not allocate; out of space")); } let r = r.unwrap(); let rlen = r.end - r.start; if len < rlen { runs.push(r.start..(r.start + len)); // We need to push something back. self.runs.push_front((r.start + len)..r.end); len = 0; } else { runs.push(r.start..r.end); len -= rlen; } } Ok(runs) } } // Having explicitly unmapped regions makes it easier to // apply snapshots. #[derive(Clone)] enum Run { Mapped { data_begin: u64, len: u64 }, UnMapped { len: u64 }, } impl Run { #[allow(dead_code)] fn len(&self) -> u64 { match self { Run::Mapped { data_begin: _data_begin, len, } => *len, Run::UnMapped { len } => *len, } } fn split(&self, n: u64) -> (Option, Option) { if n == 0 { return (None, Some(self.clone())); } else { if self.len() <= n { return (Some(self.clone()), None); } else { match self { Run::Mapped { data_begin, len } => ( Some(Run::Mapped { data_begin: *data_begin, len: n, }), Some(Run::Mapped { data_begin: data_begin + n, len: len - n, }), ), Run::UnMapped { len } => ( Some(Run::UnMapped { len: n }), Some(Run::UnMapped { len: len - n }), ), } } } } } #[derive(Clone)] struct ThinDev { thin_id: u32, dev_size: u64, runs: Vec, } impl ThinDev { fn emit(&self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { v.device_b(&xml::Device { dev_id: self.thin_id, mapped_blocks: self.dev_size, transaction: 0, creation_time: 0, snap_time: 0, })?; let mut b = 0; for r in &self.runs { match r { Run::Mapped { data_begin, len } => { v.map(&xml::Map { thin_begin: b, data_begin: *data_begin, time: 0, len: *len, })?; b += len; } Run::UnMapped { len } => { b += len; } } } v.device_e()?; Ok(()) } } #[derive(Clone)] enum SnapRunType { Same, Diff, Hole, } #[derive(Clone)] struct SnapRun(SnapRunType, u64); fn mk_origin(thin_id: u32, total_len: u64, allocator: &mut Allocator) -> Result { let mut runs = Vec::new(); let mut b = 0; while b < total_len { let len = u64::min(thread_rng().gen_range(16, 64), total_len - b); match thread_rng().gen_range(0, 2) { 0 => { for data in allocator.alloc(len)? { assert!(data.end >= data.start); runs.push(Run::Mapped { data_begin: data.start, len: data.end - data.start, }); } } 1 => { runs.push(Run::UnMapped { len }); } _ => { return Err(anyhow!("bad value returned from rng")); } }; b += len; } Ok(ThinDev { thin_id, dev_size: total_len, runs, }) } fn mk_snap_mapping( total_len: u64, run_len: Range, same_percent: usize, diff_percent: usize, ) -> Vec { let mut runs = Vec::new(); let mut b = 0u64; while b < total_len { let len = u64::min( total_len - b, thread_rng().gen_range(run_len.start, run_len.end), ); let n = thread_rng().gen_range(0, 100); if n < same_percent { runs.push(SnapRun(SnapRunType::Same, len)); } else if n < diff_percent { runs.push(SnapRun(SnapRunType::Diff, len)); } else { runs.push(SnapRun(SnapRunType::Hole, len)); } b += len; } runs } fn split_runs(mut n: u64, runs: &Vec) -> (Vec, Vec) { let mut before = Vec::new(); let mut after = Vec::new(); for r in runs { match r.split(n) { (Some(lhs), None) => { before.push(lhs); } (Some(lhs), Some(rhs)) => { before.push(lhs); after.push(rhs); } (None, Some(rhs)) => { after.push(rhs); } (None, None) => {} } n -= r.len(); } (before, after) } fn apply_snap_runs( origin: &Vec, snap: &Vec, allocator: &mut Allocator, ) -> Result> { let mut origin = origin.clone(); let mut runs = Vec::new(); for SnapRun(st, slen) in snap { let (os, rest) = split_runs(*slen, &origin); match st { SnapRunType::Same => { for o in os { runs.push(o); } } SnapRunType::Diff => { for data in allocator.alloc(*slen)? { runs.push(Run::Mapped { data_begin: data.start, len: data.end - data.start, }); } } SnapRunType::Hole => { runs.push(Run::UnMapped { len: *slen }); } } origin = rest; } Ok(runs) } // Snapshots share mappings, not neccessarily the entire ranges. pub struct SnapS { pub len: u64, pub nr_snaps: u32, // Snaps will differ from the origin by this percentage pub percent_change: usize, pub old_nr_data_blocks: u64, pub new_nr_data_blocks: u64, } impl SnapS { pub fn new(len: u64, nr_snaps: u32, percent_change: usize) -> Self { let delta = len * (nr_snaps as u64) * (percent_change as u64) / 100; let old_nr_data_blocks = len + 3 * delta; let new_nr_data_blocks = len + 2 * delta; SnapS { len, nr_snaps, percent_change, old_nr_data_blocks, new_nr_data_blocks, } } } impl XmlGen for SnapS { fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { let mut allocator = Allocator::new_shuffled(self.old_nr_data_blocks, 64..512); let origin = mk_origin(0, self.len, &mut allocator)?; v.superblock_b(&common_sb(self.old_nr_data_blocks))?; origin.emit(v)?; v.superblock_e()?; Ok(()) } } //------------------------------------------