cod-dicomweb-server/dist/esm/fileManager.js

A wadors server proxy that get data from a Cloud Optimized Dicom format.

class FileManager {
    files = {};
    set(url, file) {
        this.files[url] = { ...file, lastModified: Date.now() };
    }
    get(url, offsets) {
        if (!this.files[url] || (offsets && this.files[url].position <= offsets.endByte)) {
            return null;
        }
        return offsets ? this.files[url].data.slice(offsets.startByte, offsets.endByte) : this.files[url].data;
    }
    setPosition(url, position) {
        if (this.files[url]) {
            this.files[url].position = position;
            this.files[url].lastModified = Date.now();
        }
    }
    getPosition(url) {
        return this.files[url]?.position;
    }
    append(url, chunk, position) {
        if (this.files[url] && position) {
            this.files[url].data.set(chunk, position - chunk.length);
            this.setPosition(url, position);
        }
    }
    getTotalSize() {
        return Object.values(this.files).reduce((total, { data }) => {
            return total + data.byteLength;
        }, 0);
    }
    remove(url) {
        try {
            delete this.files[url];
            console.log(`Removed ${url} from CodDicomwebServer cache`);
        }
        catch (error) {
            console.warn(`Error removing ${url} from CodDicomwebServer cache:`, error);
        }
    }
    purge() {
        const fileURLs = Object.keys(this.files);
        const totalSize = this.getTotalSize();
        fileURLs.forEach((url) => this.remove(url));
        console.log(`Purged ${totalSize - this.getTotalSize()} bytes from CodDicomwebServer cache`);
    }
    decacheNecessaryBytes(url, bytesNeeded) {
        const totalSize = this.getTotalSize();
        const filesToDelete = [];
        let collectiveSize = 0;
        Object.entries(this.files)
            .sort(([, a], [, b]) => a.lastModified - b.lastModified)
            .forEach(([key, file]) => {
            if (collectiveSize < bytesNeeded && key !== url) {
                filesToDelete.push(key);
                collectiveSize += file.data.byteLength;
            }
        });
        filesToDelete.forEach((key) => this.remove(key));
        console.log(`Decached ${totalSize - this.getTotalSize()} bytes`);
        return collectiveSize;
    }
}
export default FileManager;