Function applyChunkedInodeUpdate

packages/dofs/src/fs/writeFile.ts:425–479

(
  db: Database,
  inode: number,
  size: number,
  mode: number,
  mtime: number,
  isTouched: (idx: number, start: number, end: number) => boolean,
  buildChunkBytes: (idx: number, start: number, end: number, existing: Uint8Array) => Uint8Array,
)

// rowids and the surrounding rows do not churn. The manifest is
// invalidated rather than recomputed; sync rebuilds it lazily.
function applyChunkedInodeUpdate(
  db: Database,
  inode: number,
  size: number,
  mode: number,
  mtime: number,
  isTouched: (idx: number, start: number, end: number) => boolean,
  buildChunkBytes: (idx: number, start: number, end: number, existing: Uint8Array) => Uint8Array,
): void {
  const oldChunks = existingChunkRefs(db, inode);
  const chunkCount = Math.ceil(size / CHUNK_SIZE);
  const oldChunkCount = oldChunks.length;

  for (let idx = 0; idx < chunkCount; idx++) {
    const start = idx * CHUNK_SIZE;
    const end = Math.min(start + CHUNK_SIZE, size);
    const intendedSize = end - start;
    const old = oldChunks[idx];
    const touched = isTouched(idx, start, end);
    // Stable chunk: existed before with the same logical size and the
    // caller did not flag it as touched. Skip without issuing SQL so
    // its rowid stays put.
    if (old !== undefined && old.size === intendedSize && !touched) continue;

    const existingBytes = old !== undefined ? readChunkBytes(db, inode, idx) : new Uint8Array();
    const chunkBytes = buildChunkBytes(idx, start, end, existingBytes);
    if (chunkBytes.byteLength !== intendedSize) {
      throw createWorkspaceError("EIO", "chunk builder returned wrong size");
    }
    const chunk = { hash: sha256(chunkBytes), bytes: chunkBytes, size: chunkBytes.byteLength };
    upsertChunkBlob(db, chunk, mtime);
    db.run(
      "INSERT OR REPLACE INTO vfs_chunks (inode, idx, hash, size) VALUES (?, ?, ?, ?)",
      inode,
      idx,
      chunk.hash,
      chunk.size,
    );
  }

  // Drop any old chunks past the new end of file (shrink case).
  if (oldChunkCount > chunkCount) {
    db.run("DELETE FROM vfs_chunks WHERE inode = ? AND idx >= ?", inode, chunkCount);
  }

  const rev = incrementRev(db);
  db.run(
    "UPDATE vfs_nodes SET mode = ?, mtime = ?, rev = ?, size = ?, manifest_hash = NULL WHERE inode = ?",
    mode,
    mtime,
    rev,
    size,
    inode,
  );
}

export function createFileSync(
  db: Database,