HTTP helpers (bottle_utils.http)

This module provides decorators for working with HTTP headers and other aspects of HTTP.

Module contents

bottle_utils.http.format_ts(seconds=None)

Given a timestamp in seconds since UNIX epoch, return a string representation suitable for use in HTTP headers according to RFC.

If seconds is omitted, the time is asumed to be current time.

bottle_utils.http.get_mimetype(filename)

Guess mime-type based on file’s extension.

bottle_utils.http.iter_read_range(fd, offset, length, chunksize=1048576)

Return an iterator that allows reading files in chunks. The fd should be a file-like object that has a read() method. The offset value sets the start offset of the read. If the fd object does not support seek(), the file will be simply read up until offset, and the read data discarded.

length argument specifies the amount of data to read. The read is not done in one go, but in chunks. The size of a chunk is specified using chunksize.

This function is similar to bottle._file_iter_range but does not fail on missing seek() attribute (e.g., StringIO objects).

bottle_utils.http.no_cache(func)

Disable caching on a handler. The decorated handler will have Cache-Control header set to private, no-cache.

This is useful for responses that contain data that cannot be reused.

Simply deocrate a handler with it:

@app.get('/foo')
@no_cache
def not_cached():
    return 'sensitive data'

bottle_utils.http.send_file(content, filename, size=None, timestamp=None)

Convert file data into an HTTP response.

This method is used when the file data does not exist on disk, such as when it is dynamically generated.

Because the file does not exist on disk, the basic metadata which is usually read from the file itself must be supplied as arguments. The filename argument is the supposed filename of the file data. It is only used to set the Content-Type header, and you may safely pass in just the extension with leading period.

The size argument is the payload size in bytes. For streaming files, this can be particularly important as the ranges are calculated baed on content length. If size is omitted, then support for ranges is not advertise and ranges are never returned.

timestamp is expected to be in seconds since UNIX epoch, and is used to calculate Last-Modified HTTP headers, as well as handle If-Modified-Since header. If omitted, current time is used, and If-Modified-Since is never checked.

Note

The returned response is a completely new response object. Modifying the reponse object in the current request context is not going to affect the object returned by this function. You should modify the object returned by this function instead.

Example:

def some_handler():
    import StringIO
    f = StringIO.StringIO('foo')
    return send_file(f, 'file.txt', 3, 1293281312)

The code is partly based on bottle.static_file, with the main difference being the use of file-like objects instead of files on disk.