[pbs-devel] [PATCH v2 backup 1/5] add and implement chunk_from_offset for IndexFile
Stefan Reiter
s.reiter at proxmox.com
Wed Jul 22 15:56:21 CEST 2020
Necessary for byte-wise seeking through chunks in an index.
Signed-off-by: Stefan Reiter <s.reiter at proxmox.com>
---
src/backup/dynamic_index.rs | 18 ++++++++++++++++++
src/backup/fixed_index.rs | 11 +++++++++++
src/backup/index.rs | 3 +++
3 files changed, 32 insertions(+)
diff --git a/src/backup/dynamic_index.rs b/src/backup/dynamic_index.rs
index 4907fe1f..887b7cf3 100644
--- a/src/backup/dynamic_index.rs
+++ b/src/backup/dynamic_index.rs
@@ -216,6 +216,24 @@ impl IndexFile for DynamicIndexReader {
digest: self.index[pos].digest.clone(),
})
}
+
+ fn chunk_from_offset(&self, offset: u64) -> Option<(usize, u64)> {
+ let end_idx = self.index.len() - 1;
+ let end = self.chunk_end(end_idx);
+ let found_idx = self.binary_search(0, 0, end_idx, end, offset);
+ let found_idx = match found_idx {
+ Ok(i) => i,
+ Err(_) => return None
+ };
+
+ let found_start = if found_idx == 0 {
+ 0
+ } else {
+ self.chunk_end(found_idx - 1)
+ };
+
+ Some((found_idx, offset - found_start))
+ }
}
struct CachedChunk {
diff --git a/src/backup/fixed_index.rs b/src/backup/fixed_index.rs
index 73d0dad0..b7e785d6 100644
--- a/src/backup/fixed_index.rs
+++ b/src/backup/fixed_index.rs
@@ -219,6 +219,17 @@ impl IndexFile for FixedIndexReader {
(csum, chunk_end)
}
+
+ fn chunk_from_offset(&self, offset: u64) -> Option<(usize, u64)> {
+ if offset >= self.size {
+ return None;
+ }
+
+ Some((
+ (offset / self.chunk_size as u64) as usize,
+ offset % self.chunk_size as u64
+ ))
+ }
}
pub struct FixedIndexWriter {
diff --git a/src/backup/index.rs b/src/backup/index.rs
index efdf3b54..2eab8524 100644
--- a/src/backup/index.rs
+++ b/src/backup/index.rs
@@ -22,6 +22,9 @@ pub trait IndexFile {
fn index_bytes(&self) -> u64;
fn chunk_info(&self, pos: usize) -> Option<ChunkReadInfo>;
+ /// Get the chunk index and the relative offset within it for a byte offset
+ fn chunk_from_offset(&self, offset: u64) -> Option<(usize, u64)>;
+
/// Compute index checksum and size
fn compute_csum(&self) -> ([u8; 32], u64);
--
2.20.1
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