Function direct_upload 

pub fn direct_upload(
    ctx: &Ctx,
    prefix: &str,
    field: &str,
    request: &DirectUploadRequest,
    rules: &Rules,
) -> Result<DirectUpload>

Starts a direct upload: checks what the browser declares against rules and presigns a PUT of a new key under prefix.

Rails’ DirectUploadsController#create. The browser PUTs the file to DirectUpload::url with DirectUpload::headers (within 10 minutes), then submits DirectUpload::signed_key with its form; attach_direct_upload checks the stored object and returns its Attachment. The file never passes through the Worker: no 100 MB request limit, no Worker memory or CPU. The key is <prefix>/<22 random characters>; use a prefix of its own (uploads/photos) so purge_unattached can find abandoned uploads.

Settings as presign_get; the bucket also needs a CORS rule allowing PUT from the app’s origin (see the file storage guide). Signing costs no R2 operation; the upload is one class A operation.

Errors

• Error::Invalid (422) on field when the declared size or type breaks rules.
• Error::Internal (500) when an R2_* setting is missing.

Examples

use axum::{Json, extract::State};
use ocre::storage::{self, DirectUpload, DirectUploadRequest, Rules};
use ocre::{ApiResult, Ctx};

const VIDEO: Rules = Rules { max_bytes: 500 * 1024 * 1024, content_types: &["video/mp4"] };

// POST /videos/uploads with {"filename": "a.mp4", "content_type": "video/mp4", "size": 1234}
async fn start(State(ctx): State<Ctx>, Json(request): Json<DirectUploadRequest>) -> ApiResult<Json<DirectUpload>> {
    Ok(Json(storage::direct_upload(&ctx, "uploads/videos", "video", &request, &VIDEO)?))
}