handle concurrence in bot

.github/scripts/assign_xls_number.py

@@ -10,7 +10,9 @@
 import os
 import re
 import sys
+import json
 from pathlib import Path
+from urllib import error, parse, request
 
 
 def get_existing_xls_numbers(repo_root: Path) -> set[int]:
@@ -74,6 +76,138 @@ def find_draft_xls_files(changed_files: list[str]) -> list[str]:
     return list(set(drafts))  # Remove duplicates
 
 
+def github_api_request(path: str, token: str, params: dict | None = None):
+    """Small helper to call the GitHub REST API.
+
+    Returns parsed JSON or an empty list/dict on failure.
+    """
+
+    base_url = "https://api.github.com"
+    url = f"{base_url}{path}"
+    if params:
+        query = parse.urlencode(params)
+        url = f"{url}?{query}"
+
+    headers = {
+        "Accept": "application/vnd.github+json",
+        "User-Agent": "xrpl-standards-xls-number-bot",
+    }
+    if token:
+        headers["Authorization"] = f"Bearer {token}"
+
+    req = request.Request(url, headers=headers)
+
+    try:
+        with request.urlopen(req) as resp:
+            data = resp.read()
+        return json.loads(data.decode("utf-8"))
+    except error.HTTPError as e:
+        print(f"Warning: GitHub API HTTP error {e.code} for {url}: {e.reason}")
+    except error.URLError as e:
+        print(f"Warning: GitHub API URL error for {url}: {e.reason}")
+
+    # On any failure, return an empty list so callers can treat it as "no data".
+    return []
+
+
+def extract_xls_number_from_comments(
+    owner: str, repo: str, token: str, issue_number: int
+) -> int | None:
+    """Extract reserved XLS number for an issue/PR from bot comments.
+
+    Looks for a marker of the form: <!-- XLS_NUMBER:0123 --> in comments
+    authored by github-actions[bot].
+    """
+
+    page = 1
+    while True:
+        comments = github_api_request(
+            f"/repos/{owner}/{repo}/issues/{issue_number}/comments",
+            token,
+            {"per_page": 100, "page": page},
+        )
+
+        if not comments:
+            break
+
+        for comment in comments:
+            if comment.get("user", {}).get("login") != "github-actions[bot]":
+                continue
+            body = comment.get("body") or ""
+            match = re.search(r"<!--\s*XLS_NUMBER:(\\d+)\s*-->", body)
+            if match:
+                try:
+                    return int(match.group(1))
+                except ValueError:
+                    continue
+
+        if len(comments) < 100:
+            break
+        page += 1
+
+    return None
+
+
+def get_reserved_xls_numbers_from_prs(
+    token: str, repo: str, current_pr_number: int | None
+) -> tuple[set[int], int | None]:
+    """Find XLS numbers reserved by open PRs with the 'has-xls-number' label.
+
+    Returns a tuple of (set of reserved numbers, number assigned to the current PR
+    if any).
+    """
+
+    if not token or not repo:
+        # Without a token or repo, we cannot query the API; treat as no reservations.
+        return set(), None
+
+    if "/" not in repo:
+        return set(), None
+
+    owner, repo_name = repo.split("/", 1)
+
+    reserved_numbers: set[int] = set()
+    current_pr_assigned: int | None = None
+
+    page = 1
+    while True:
+        issues = github_api_request(
+            f"/repos/{owner}/{repo_name}/issues",
+            token,
+            {
+                "state": "open",
+                "labels": "has-xls-number",
+                "per_page": 100,
+                "page": page,
+            },
+        )
+
+        if not issues:
+            break
+
+        for issue in issues:
+            # Filter to PRs only
+            if "pull_request" not in issue:
+                continue
+
+            issue_number = issue.get("number")
+            num = extract_xls_number_from_comments(owner, repo_name, token, issue_number)
+            if num is None:
+                continue
+
+            reserved_numbers.add(num)
+
+            if current_pr_number is not None and issue_number == current_pr_number:
+                current_pr_assigned = num
+
+        if len(issues) < 100:
+            break
+
+        page += 1
+
+    return reserved_numbers, current_pr_assigned
+
+
 def main():
     """Main entry point for the script."""
     # Get repository root from environment variable (set by GitHub Actions)
@@ -116,24 +250,56 @@ def set_github_output(name: str, value: str):
         set_github_output("has_drafts", "false")
         return
 
-    # Get existing XLS numbers
+    # Discover reserved XLS numbers from other open PRs and from this PR (if any)
+    github_token = os.environ.get("GITHUB_TOKEN", "")
+    github_repo = os.environ.get("GITHUB_REPOSITORY", "")
+    current_pr_number = None
+    event_path = os.environ.get("GITHUB_EVENT_PATH")
+    if event_path and os.path.isfile(event_path):
+        try:
+            with open(event_path, "r", encoding="utf-8") as f:
+                event = json.load(f)
+            current_pr_number = event.get("pull_request", {}).get("number")
+        except Exception as exc:  # pragma: no cover - defensive
+            print(f"Warning: Failed to parse GITHUB_EVENT_PATH: {exc}")
+
+    reserved_numbers, current_pr_assigned = get_reserved_xls_numbers_from_prs(
+        github_token,
+        github_repo,
+        current_pr_number,
+    )
+
+    if reserved_numbers:
+        print(f"Found {len(reserved_numbers)} XLS numbers reserved by open PRs.")
+
+    # Get existing XLS numbers from the base branch
     existing_numbers = get_existing_xls_numbers(repo_root)
-    print(f"Found {len(existing_numbers)} existing XLS numbers.")
+    print(f"Found {len(existing_numbers)} existing XLS numbers in the repository.")
     print(f"Highest existing number: {max(existing_numbers) if existing_numbers else 0}")
 
-    # Assign numbers to each draft
-    next_number = get_next_xls_number(existing_numbers)
+    all_numbers = existing_numbers | reserved_numbers
+
     assignments = []
 
+    if current_pr_assigned is not None:
+        print(
+            f"Reusing previously reserved XLS number {current_pr_assigned:04d} for this PR."
+        )
+        next_number = current_pr_assigned
+    else:
+        next_number = get_next_xls_number(all_numbers)
+
     for draft_dir in sorted(draft_dirs):
         assigned_number = next_number
+        all_numbers.add(assigned_number)
         new_dir_name = re.sub(r"^xls-draft-", f"xls-{assigned_number:04d}-", draft_dir.lower())
         assignments.append({
             "draft": draft_dir,
             "number": assigned_number,
             "new_name": new_dir_name,
         })
-        next_number += 1
+        # Calculate the next free number for any additional drafts
+        next_number = get_next_xls_number(all_numbers)
 
     # Output results
     print("\n=== XLS Number Assignments ===")

.github/workflows/assign-xls-number.yml

@@ -4,6 +4,10 @@ on:
   pull_request_target:
     types: [opened, synchronize, reopened, ready_for_review]
 
+concurrency:
+  group: assign-xls-number-${{ github.repository }}
+  cancel-in-progress: false
+
 jobs:
   assign-xls-number:
     runs-on: ubuntu-latest
@@ -78,10 +82,11 @@ jobs:
           body-includes: "XLS Number Assignment"
 
       - name: Post or update PR comment
-        if: steps.check-drafts.outputs.has_drafts == 'true' && steps.find-comment.outputs.comment-id == ''
+        if: steps.check-drafts.outputs.has_drafts == 'true'
         uses: peter-evans/create-or-update-comment@v5
         with:
           issue-number: ${{ github.event.pull_request.number }}
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
           body: |
             ## 🎫 XLS Number Assignment
 
@@ -101,4 +106,18 @@ jobs:
                - Set `status:` to `Draft`
 
             ---
-            *This comment was automatically generated. The XLS number is based on the highest existing number in the repository at the time this PR was opened.*
+            *This comment was automatically generated. The XLS number below is reserved for this PR based on existing XLS numbers in the repository and other open draft PRs.*
+
+            <!-- XLS_NUMBER:${{ steps.assign-number.outputs.xls_number }} -->
+
+      - name: Add has-xls-number label
+        if: steps.check-drafts.outputs.has_drafts == 'true'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          curl -sS \
+            -H "Authorization: Bearer $GITHUB_TOKEN" \
+            -H "Accept: application/vnd.github+json" \
+            -X POST \
+            -d '{"labels":["has-xls-number"]}' \
+            "https://api.github.com/repos/${{ github.repository }}/issues/${{ github.event.pull_request.number }}/labels"