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Relax revision-update check

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This commit is contained in:
Tom Russell 2018-10-05 21:44:51 +01:00
parent b438e885c0
commit 2b29d01a21
1 changed files with 7 additions and 9 deletions
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16
app/src/building.js
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@ -76,11 +76,11 @@ function getBuildingById(id) {
}
function saveBuilding(building_id, building, user_id) {
// save building must fail if the revision seen by the user != the latest revision
// - any 'intuitive' retries to be handled by clients of this code
// save building could fail if the revision seen by the user != the latest revision
// - any 'intuitive' retries would need to be handled by clients of this code
// revision id allows for a long user 'think time' between view-building, update-building
// (optimistic locking implemented using field-based row versioning)
const previous_revision_id = building.revision_id;
// const previous_revision_id = building.revision_id;
// remove read-only fields from consideration
delete building.building_id;
@ -93,10 +93,9 @@ function saveBuilding(building_id, building, user_id) {
// - update to latest state
// commit or rollback (repeated-read sufficient? or serializable?)
return db.tx(t => {
const check_revision = (previous_revision_id)? "and revision_id = $2" : "";
return t.one(
`SELECT * FROM buildings WHERE building_id = $1 ${check_revision} FOR UPDATE;`,
[building_id, previous_revision_id]
`SELECT * FROM buildings WHERE building_id = $1 FOR UPDATE;`,
[building_id]
).then(old_building => {
const patches = compare(old_building, building, BUILDING_FIELD_WHITELIST);
console.log("Patching", patches)
@ -116,7 +115,6 @@ function saveBuilding(building_id, building, user_id) {
).then(revision => {
const sets = db.$config.pgp.helpers.sets(forward);
console.log("Setting", sets)
const check_revision = (previous_revision_id)? "AND revision_id = $4" : "";
return t.one(
`UPDATE
buildings
@ -124,11 +122,11 @@ function saveBuilding(building_id, building, user_id) {
revision_id = $1,
$2:raw
WHERE
building_id = $3 ${check_revision}
building_id = $3
RETURNING
*
`,
[revision.log_id, sets, building_id, previous_revision_id]
[revision.log_id, sets, building_id]
)
});
});