1
0
Fork 0
mirror of https://github.com/vbatts/go-mtree.git synced 2025-09-13 22:03:19 +00:00

compare: improve tar_time truncation

Rather than parsing the value as a float and then truncating it, just
parse it as an integer in the first place (this also adds some
validation that we are parsing a reasonable-looking value).

While we're at it, add some integration tests for this code to make sure
this quite complicated special-case behaviour doesn't regress.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This commit is contained in:
Aleksa Sarai 2025-09-09 17:55:02 +10:00
parent 0beb885cbf
commit 604ab42863
No known key found for this signature in database
GPG key ID: 2897FAD2B7E9446F
2 changed files with 116 additions and 9 deletions

View file

@ -4,7 +4,6 @@ import (
"encoding/json" "encoding/json"
"fmt" "fmt"
"slices" "slices"
"strconv"
) )
// XXX: Do we need a Difference interface to make it so people can do var x // XXX: Do we need a Difference interface to make it so people can do var x
@ -253,23 +252,35 @@ func compareEntry(oldEntry, newEntry Entry) ([]KeyDelta, error) {
// Make a new tar_time. // Make a new tar_time.
if diffs["tar_time"].Old == nil { if diffs["tar_time"].Old == nil {
time, err := strconv.ParseFloat(timeStateT.Old.Value(), 64) var (
if err != nil { timeSec, timeNsec int64
return nil, fmt.Errorf("failed to parse old time: %s", err) // used to check for trailing characters
trailing rune
)
val := timeStateT.Old.Value()
n, _ := fmt.Sscanf(val, "%d.%d%c", &timeSec, &timeNsec, &trailing)
if n != 2 {
return nil, fmt.Errorf("failed to parse old time: invalid format %q", val)
} }
newTime := new(KeyVal) newTime := new(KeyVal)
*newTime = KeyVal(fmt.Sprintf("tar_time=%d.000000000", int64(time))) *newTime = KeyVal(fmt.Sprintf("tar_time=%d.%9.9d", timeSec, 0))
diffs["tar_time"].Old = newTime diffs["tar_time"].Old = newTime
} else if diffs["tar_time"].New == nil { } else if diffs["tar_time"].New == nil {
time, err := strconv.ParseFloat(timeStateT.New.Value(), 64) var (
if err != nil { timeSec, timeNsec int64
return nil, fmt.Errorf("failed to parse new time: %s", err) // used to check for trailing characters
trailing rune
)
val := timeStateT.New.Value()
n, _ := fmt.Sscanf(val, "%d.%d%c", &timeSec, &timeNsec, &trailing)
if n != 2 {
return nil, fmt.Errorf("failed to parse new time: invalid format %q", val)
} }
newTime := new(KeyVal) newTime := new(KeyVal)
*newTime = KeyVal(fmt.Sprintf("tar_time=%d.000000000", int64(time))) *newTime = KeyVal(fmt.Sprintf("tar_time=%d.%9.9d", timeSec, 0))
diffs["tar_time"].New = newTime diffs["tar_time"].New = newTime
} else { } else {

96
test/cli/0012trunc.sh Normal file
View file

@ -0,0 +1,96 @@
#!/bin/bash
set -ex
name=$(basename $0)
root="$(dirname $(dirname $(dirname $0)))"
gomtree=$(go run ${root}/test/realpath/main.go ${root}/gomtree)
t=$(mktemp -d /tmp/go-mtree.XXXXXX)
echo "[${name}] Running in ${t}"
## Make sure that comparing manifests with tar_time and time are correctly
## truncated.
pushd ${root}
mkdir -p ${t}/root
date="2025-09-05T13:05:10" # POSIX format for "touch -d".
echo "less than .5" >${t}/root/lowerhalf
touch -d "$date.1000" ${t}/root/lowerhalf
echo "more than .5" >${t}/root/upperhalf
touch -d "$date.8000" ${t}/root/upperhalf
echo "no subsecond" >${t}/root/tartime
touch -d "$date.0000" ${t}/root/tartime
keywords=type,uid,gid,nlink,link,mode,flags,xattr,size,sha256
# Generate regular manifests with time and tar_time.
${gomtree} -c -k ${keywords},time -p ${t}/root -f ${t}/time.mtree
${gomtree} -c -k ${keywords},tar_time -p ${t}/root -f ${t}/tartime.mtree
# Make sure that tar_time truncates the value.
unix="$(date -d ${date} +%s)"
grep -q "lowerhalf.*tar_time=$unix.000000000" ${t}/tartime.mtree
grep -q "upperhalf.*tar_time=$unix.000000000" ${t}/tartime.mtree
grep -q "tartime.*tar_time=$unix.000000000" ${t}/tartime.mtree
# Validation with both manifests should still succeed.
${gomtree} validate -p ${t}/root -f ${t}/time.mtree
${gomtree} validate -p ${t}/root -f ${t}/tartime.mtree
# Manifest comparison should also succeed.
${gomtree} validate -f ${t}/tartime.mtree -f ${t}/time.mtree
${gomtree} validate -f ${t}/time.mtree -f ${t}/tartime.mtree
# Truncate the on-disk timestamps manually.
touch -d "$date.0000" ${t}/root/lowerhalf
touch -d "$date.0000" ${t}/root/upperhalf
touch -d "$date.0000" ${t}/root/tartime
# Only the tar_time manifest should succeed.
(! ${gomtree} validate -p ${t}/root -f ${t}/time.mtree)
${gomtree} validate -p ${t}/root -f ${t}/tartime.mtree
${gomtree} validate -k ${keywords},time -p ${t}/root -f ${t}/tartime.mtree
# ... unless you force the usage of tar_time.
${gomtree} validate -k ${keywords},tar_time -p ${t}/root -f ${t}/time.mtree
# The same goes for if you generate the manifests and compare them instead.
${gomtree} -c -k ${keywords},time -p ${t}/root -f ${t}/time-trunc.mtree
${gomtree} -c -k ${keywords},tar_time -p ${t}/root -f ${t}/tartime-trunc.mtree
# Comparing time with time should fail ...
(! ${gomtree} validate -f ${t}/time.mtree -f ${t}/time-trunc.mtree)
(! ${gomtree} validate -f ${t}/time-trunc.mtree -f ${t}/time.mtree)
# ... tar_time with tar_time should succeed ...
${gomtree} validate -f ${t}/tartime.mtree -f ${t}/tartime-trunc.mtree
${gomtree} validate -f ${t}/tartime-trunc.mtree -f ${t}/tartime.mtree
# ... old tar_time with new time should succeed ...
${gomtree} validate -f ${t}/tartime.mtree -f ${t}/time-trunc.mtree
${gomtree} validate -f ${t}/time-trunc.mtree -f ${t}/tartime.mtree
# ... and new tar_time against old time should succeed.
${gomtree} validate -f ${t}/tartime-trunc.mtree -f ${t}/time.mtree
${gomtree} validate -f ${t}/time.mtree -f ${t}/tartime-trunc.mtree
# Change the timestamp entirely.
touch -d "1997-03-25T13:40:00" ${t}/root/lowerhalf
touch -d "1997-03-25T13:40:00" ${t}/root/upperhalf
touch -d "1997-03-25T13:40:00" ${t}/root/tartime
# Now all validations should fail.
(! ${gomtree} validate -p ${t}/root -f ${t}/time.mtree)
(! ${gomtree} validate -p ${t}/root -f ${t}/tartime.mtree)
(! ${gomtree} validate -k ${keywords},tar_time -p ${t}/root -f ${t}/time.mtree)
(! ${gomtree} validate -k ${keywords},time -p ${t}/root -f ${t}/tartime.mtree)
# Ditto for generating the manifests and comparing them.
${gomtree} -c -k ${keywords},time -p ${t}/root -f ${t}/time-change.mtree
${gomtree} -c -k ${keywords},tar_time -p ${t}/root -f ${t}/tartime-change.mtree
# Try all combinations.
lefts=( ${t}/{tar,}time{,-trunc}.mtree )
rights=( ${t}/{tar,}time-change.mtree )
for left in "${lefts[@]}"; do
for right in "${rights[@]}"; do
(! ${gomtree} validate -f ${left} -f ${right})
(! ${gomtree} validate -f ${right} -f ${left})
done
done