XrdHttpReadRangeHandler Class Reference

#include <XrdHttpReadRangeHandler.hh>

Collaboration diagram for XrdHttpReadRangeHandler:

Classes
struct	Configuration
struct	Error
struct	UserRange

Public Types
typedef std::vector< UserRange >	UserRangeList

Public Member Functions
	XrdHttpReadRangeHandler (const Configuration &conf)
const Error &	getError () const
bool	isFullFile ()
bool	isSingleRange ()
const UserRangeList &	ListResolvedRanges ()
const XrdHttpIOList &	NextReadList ()
void	NotifyError ()
int	NotifyReadResult (const ssize_t ret, const UserRange **const urp, bool &start, bool &allend)
void	ParseContentRange (const char *const line)
void	reset ()
int	SetFilesize (const off_t sz)

Static Public Member Functions
static int	Configure (XrdSysError &Eroute, const char *const parms, Configuration &cfg)

Static Public Attributes
static constexpr size_t	READV_MAXCHUNKS = 512
static constexpr size_t	READV_MAXCHUNKSIZE = 512*1024
static constexpr size_t	RREQ_MAXSIZE = 8*1024*1024

Private Member Functions
int	parseOneRange (char *const str)
int	rangeFig (const char *const s, bool &set, off_t &start)
void	resolveRanges ()
void	splitRanges ()
void	trimSplit ()

Private Attributes
Error	error_
UserRangeList	rawUserRanges_
bool	rangesResolved_
UserRangeList	resolvedUserRanges_
XrdHttpIOList	splitRange_
size_t	resolvedRangeIdx_
off_t	resolvedRangeOff_
size_t	splitRangeIdx_
off_t	splitRangeOff_
size_t	currSplitRangeIdx_
int	currSplitRangeOff_
off_t	filesize_
size_t	vectorReadMaxChunkSize_
size_t	vectorReadMaxChunks_
size_t	rRequestMaxBytes_

Detailed Description

Class responsible for parsing the HTTP Content-Range header coming from the client, generating appropriate read ranges for read or readv and tracking the responses to the requests.

Member Typedef Documentation

UserRangeList

typedef std::vector<UserRange> XrdHttpReadRangeHandler::UserRangeList

Constructor & Destructor Documentation

XrdHttpReadRangeHandler()

XrdHttpReadRangeHandler::XrdHttpReadRangeHandler ( const Configuration &  conf )

inline

Constructor. Supplied with an Configuration object. The supplied object remains owned by the caller, but should remain valid throughout the lifetime of the ReadRangeHandler.

Parameters

conf Configuration object.

References XrdHttpReadRangeHandler::Configuration::haveSizes, XrdHttpReadRangeHandler::Configuration::readv_ior_max, XrdHttpReadRangeHandler::Configuration::readv_iov_max, READV_MAXCHUNKS, READV_MAXCHUNKSIZE, XrdHttpReadRangeHandler::Configuration::reqs_max, reset(), RREQ_MAXSIZE, rRequestMaxBytes_, vectorReadMaxChunks_, and vectorReadMaxChunkSize_.

Member Function Documentation

Configure()

static int XrdHttpReadRangeHandler::Configure ( XrdSysError &  Eroute, const char *const  parms, Configuration &  cfg  )

static

Parses a configuration into a Configuration object.

Parameters

Eroute Error reporting object

Parameters

parms Configuration string.

Parameters

cfg an output Configuration object

Returns

0 for success, otherwise failure.

getError()

const Error & XrdHttpReadRangeHandler::getError

(

)

const

getter for the Error object. The object can be inspected with its operator bool() method to indicate an error has happened. Error code and message are available in other members of Error.

isFullFile()

bool XrdHttpReadRangeHandler::isFullFile

(

)

Indicates no valid Range header was given and thus the implication is that whole file is required. A range or ranges may be given that cover the whole file but that situation is not detected.

isSingleRange()

bool XrdHttpReadRangeHandler::isSingleRange

(

)

Incidcates whether there is a single range, either given by a Range header with single range or implied by having no Range header. Also returns true for an empty file, although there is no range of bytes.

Returns

true if there is a single range.

ListResolvedRanges()

const UserRangeList & XrdHttpReadRangeHandler::ListResolvedRanges

(

)

Returns a reference of the list of ranges. These are resolved, meaning that if there was no Range header, or it was in the form -N or N-, the file size is used to compute the actual range of bytes that are needed. The list remains owned by the handler and may be invalidated on reset().

Returns

List of ranges in a UserRangeList object. The returned list may be empty, i.e. for an empty file or if there is an error. Use getError() to see if there is an error.

NextReadList()

const XrdHttpIOList & XrdHttpReadRangeHandler::NextReadList

(

)

Requests a XrdHttpIOList (vector of XrdOucIOVec2) that describes the next bytes that need to be fetched from a file. If there is more than one chunk it is size appropriately for a readv request, if there is one request it should be sent as a read request. Therefore the chunks do not necessarily correspond to the ranges the user requested. The caller issue the requests in the order provided and call NotifyReadResult with the ordered results.

Returns

a reference to a XrdHttpIOList. The object remains owned by the handler. It may be invalided by a new call to NextReadList() or reset(). The returned list may be empty, which implies no more reads are needed One can use getError() to see if there is an error.

NotifyError()

void XrdHttpReadRangeHandler::NotifyError

(

)

Force the handler to enter error state. Sets a generic error message if there was not already an error.

NotifyReadResult()

int XrdHttpReadRangeHandler::NotifyReadResult	(	const ssize_t	ret,
		const UserRange **const	urp,
		bool &	start,
		bool &	allend
	)

Notifies the handler about the arrival of bytes from a read or readv request. The handler tracks the progress of the arriving bytes against the bytes ranges the user requested.

Parameters

ret	the number of bytes received
urp	a pointer to a pointer of a UserRange object. If urp is not nullptr, the pointer to a UserRange is returned that describes the current range associated with the received bytes. The handler retains ownership of the returned object. reset() of the handler invalidates the UserRange object.
start	is an output bool parameter that indicates whether the received bytes mark the start of a UserRange.
allend	is an output bool parameter that indicates whether the received bytes mark the end of all the UserRanges

Returns

0 upon success, -1 if an error happened. One needs to call the getError() method to return the error.

ParseContentRange()

void XrdHttpReadRangeHandler::ParseContentRange

(

const char *const

line

)

Parses the Content-Range header value and sets the ranges within the object.

Parameters

line	the line under the format "bytes=0-19, 25-30" In case the parsing fails any partial results are cleared. There is no error notification as the rest of the request processing should continue in any case.

parseOneRange()

int XrdHttpReadRangeHandler::parseOneRange ( char *const  str )

private

rangeFig()

int XrdHttpReadRangeHandler::rangeFig ( const char *const  s, bool &  set, off_t &  start  )

private

reset()

void XrdHttpReadRangeHandler::reset

(

)

Resets the object state, ready for handling a new request.

Referenced by XrdHttpReadRangeHandler().

resolveRanges()

void XrdHttpReadRangeHandler::resolveRanges ( )

private

SetFilesize()

int XrdHttpReadRangeHandler::SetFilesize

(

const off_t

sz

)

Notifies of the current file size. This information is required for processing range requests that imply reading to the end or a certain position before the end of a file. It is also used to determine when read or readv need no longer be issued when reading the whole file. Can be called once or more, after reset() but before isSingleRange(), ListResolvedRanges() or NextReadList() methods.

Parameters

sz	the size of the file

Returns

0 upon success, -1 if an error happened. One needs to call the getError() method to return the error.

splitRanges()

void XrdHttpReadRangeHandler::splitRanges ( )

private

trimSplit()

void XrdHttpReadRangeHandler::trimSplit ( )

private

Member Data Documentation

currSplitRangeIdx_

size_t XrdHttpReadRangeHandler::currSplitRangeIdx_

private

currSplitRangeOff_

int XrdHttpReadRangeHandler::currSplitRangeOff_

private

error_

Error XrdHttpReadRangeHandler::error_

private

filesize_

off_t XrdHttpReadRangeHandler::filesize_

private

rangesResolved_

bool XrdHttpReadRangeHandler::rangesResolved_

private

rawUserRanges_

UserRangeList XrdHttpReadRangeHandler::rawUserRanges_

private

READV_MAXCHUNKS

constexpr size_t XrdHttpReadRangeHandler::READV_MAXCHUNKS = 512

staticconstexpr

These are defaults for: READV_MAXCHUNKS Max length of the XrdHttpIOList vector. READV_MAXCHUNKSIZE Max length of a XrdOucIOVec2 element. RREQ_MAXSIZE Max bytes to issue in a whole readv/read.

Referenced by XrdHttpReadRangeHandler().

READV_MAXCHUNKSIZE

constexpr size_t XrdHttpReadRangeHandler::READV_MAXCHUNKSIZE = 512*1024

staticconstexpr

Referenced by XrdHttpReadRangeHandler().

resolvedRangeIdx_

size_t XrdHttpReadRangeHandler::resolvedRangeIdx_

private

resolvedRangeOff_

off_t XrdHttpReadRangeHandler::resolvedRangeOff_

private

resolvedUserRanges_

UserRangeList XrdHttpReadRangeHandler::resolvedUserRanges_

private

RREQ_MAXSIZE

constexpr size_t XrdHttpReadRangeHandler::RREQ_MAXSIZE = 8*1024*1024

staticconstexpr

Referenced by XrdHttpReadRangeHandler().

rRequestMaxBytes_

size_t XrdHttpReadRangeHandler::rRequestMaxBytes_

private

Referenced by XrdHttpReadRangeHandler().

splitRange_

XrdHttpIOList XrdHttpReadRangeHandler::splitRange_

private

splitRangeIdx_

size_t XrdHttpReadRangeHandler::splitRangeIdx_

private

splitRangeOff_

off_t XrdHttpReadRangeHandler::splitRangeOff_

private

vectorReadMaxChunks_

size_t XrdHttpReadRangeHandler::vectorReadMaxChunks_

private

Referenced by XrdHttpReadRangeHandler().

vectorReadMaxChunkSize_

size_t XrdHttpReadRangeHandler::vectorReadMaxChunkSize_

private

Referenced by XrdHttpReadRangeHandler().

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The documentation for this class was generated from the following file:

• XrdHttpReadRangeHandler.hh