HTTP downloading is used if the server provides a content server URL in the connect message. Any missing content the client needs will then use the HTTP server. CURL is used to enable multiple files to be downloaded in parallel to improve performance on high latency links when small files such as textures are needed. Since CURL natively supports gzip content encoding, any files on the HTTP server should ideally be gzipped to conserve bandwidth. More...

#include "client.h"
#include "cl_http.h"
#include "battlescape/cl_parse.h"

Enumerations
enum	{ HTTPDL_ABORT_NONE, HTTPDL_ABORT_SOFT, HTTPDL_ABORT_HARD }

Functions
static void	StripHighBits (char *string)

static bool	isvalidchar (int c)

static int	CL_HTTP_Progress (void *clientp, double dltotal, double dlnow, double ultotal, double ulnow)
	libcurl callback to update progress info. Mainly just used as a way to cancel the transfer if required. More...

static void	CL_EscapeHTTPPath (const char filePath, char escaped)
	Properly escapes a path with HTTP encoding. libcurl's function seems to treat '/' and such as illegal chars and encodes almost the entire URL... More...

static void	CL_StartHTTPDownload (dlqueue_t entry, dlhandle_t dl)
	Actually starts a download by adding it to the curl multi handle. More...

void	CL_SetHTTPServer (const char *URL)
	A new server is specified, so we nuke all our state. More...

void	CL_CancelHTTPDownloads (bool permKill)
	Cancel all downloads and nuke the queue. More...

static dlhandle_t *	CL_GetFreeDLHandle (void)
	Find a free download handle to start another queue entry on. More...

bool	CL_QueueHTTPDownload (const char *ufoPath)
	Called from the precache check to queue a download. More...

bool	CL_PendingHTTPDownloads (void)
	See if we're still busy with some downloads. Called by precacher just before it loads the map since we could be downloading the map. If we're busy still, it'll wait and CL_FinishHTTPDownload will pick up from where it left. More...

bool	CL_CheckOrDownloadFile (const char *filename)

static void	CL_CheckAndQueueDownload (char *path)
	Validate a path supplied by a filelist. More...

static void	CL_ParseFileList (dlhandle_t *dl)
	A filelist is in memory, scan and validate it and queue up the files. More...

static void	CL_ReVerifyHTTPQueue (void)
	A pk3 file just downloaded, let's see if we can remove some stuff from the queue which is in the .pk3. More...

void	CL_HTTP_Cleanup (void)
	UFO is exiting or we're changing servers. Clean up. More...

static void	CL_FinishHTTPDownload (void)
	A download finished, find out what it was, whether there were any errors and if so, how severe. If none, rename file and other such stuff. More...

static void	CL_StartNextHTTPDownload (void)
	Start another HTTP download if possible. More...

void	CL_RunHTTPDownloads (void)
	This calls curl_multi_perform do actually do stuff. Called every frame while connecting to minimise latency. Also starts new downloads if we're not doing the maximum already. More...

void	HTTP_InitStartup (void)

Variables
static cvar_t *	cl_http_downloads

static cvar_t *	cl_http_filelists

static cvar_t *	cl_http_max_connections

static CURLM *	multi = nullptr

static int	handleCount = 0

static int	pendingCount = 0

static int	abortDownloads = HTTPDL_ABORT_NONE

static bool	downloadingPK3 = false

Detailed Description

HTTP downloading is used if the server provides a content server URL in the connect message. Any missing content the client needs will then use the HTTP server. CURL is used to enable multiple files to be downloaded in parallel to improve performance on high latency links when small files such as textures are needed. Since CURL natively supports gzip content encoding, any files on the HTTP server should ideally be gzipped to conserve bandwidth.

Author: R1CH

See also: CL_ConnectionlessPacket; SVC_DirectConnect

Definition in file cl_http.cpp.

Enumeration Type Documentation

anonymous enum

Enumerator
HTTPDL_ABORT_NONE
HTTPDL_ABORT_SOFT
HTTPDL_ABORT_HARD

Definition at line 44 of file cl_http.cpp.

Function Documentation

void CL_CancelHTTPDownloads ( bool permKill )

Cancel all downloads and nuke the queue.

Definition at line 250 of file cl_http.cpp.

References abortDownloads, cls, DLQ_STATE_DONE, DLQ_STATE_NOT_STARTED, client_static_s::downloadQueue, client_static_s::downloadServer, handleCount, HTTPDL_ABORT_HARD, HTTPDL_ABORT_SOFT, dlqueue_s::next, and pendingCount.

Referenced by CL_FinishHTTPDownload(), and CL_RunHTTPDownloads().

static void CL_CheckAndQueueDownload ( char * path )

static

Validate a path supplied by a filelist.

Parameters

[in,out] path Pointer to file (path) to download (high bits will be stripped).

See also: CL_QueueHTTPDownload; CL_ParseFileList

Definition at line 391 of file cl_http.cpp.

References CL_CheckOrDownloadFile(), CL_QueueHTTPDownload(), cls, Com_GetExtension(), Com_Printf(), Com_sprintf(), client_static_s::downloadQueue, f, FILE, FS_CheckFile(), FS_Gamedir(), isvalidchar(), length, MAX_OSPATH, MAX_QPATH, dlqueue_s::next, Q_streq, StripHighBits(), and Sys_Fopen().

Referenced by CL_ParseFileList().

bool CL_CheckOrDownloadFile ( const char * filename )

Returns: true if the file exists, otherwise it attempts to start a download via curl

See also: CL_CheckAndQueueDownload; CL_RequestNextDownload

Definition at line 341 of file cl_http.cpp.

References CL_QueueHTTPDownload(), Com_Printf(), FS_LoadFile(), MAX_OSPATH, Q_streq, Q_strncpyz(), and Q_strnull().

Referenced by CL_CheckAndQueueDownload(), CL_DownloadMap(), and CL_DownloadUMPMap().

static void CL_EscapeHTTPPath	(	const char *	filePath,
		char *	escaped
	)

static

Properly escapes a path with HTTP encoding. libcurl's function seems to treat '/' and such as illegal chars and encodes almost the entire URL...

Definition at line 106 of file cl_http.cpp.

References i, and len.

Referenced by CL_StartHTTPDownload().

static void CL_FinishHTTPDownload ( void )

static

A download finished, find out what it was, whether there were any errors and if so, how severe. If none, rename file and other such stuff.

Todo:: technically i shouldn't need to do this as curl will auto reuse the existing handle when you change the URL. however, the handleCount goes all weird when reusing a download slot in this way. if you can figure out why, please let me know.

Definition at line 566 of file cl_http.cpp.

References abortDownloads, ca_connected, CL_CancelHTTPDownloads(), CL_ParseFileList(), CL_PendingHTTPDownloads(), CL_RequestNextDownload(), CL_ReVerifyHTTPQueue(), cls, Com_Error(), Com_GetExtension(), Com_Printf(), Com_sprintf(), dlhandle_s::curl, DLQ_STATE_DONE, downloadingPK3, client_static_s::downloadName, client_static_s::downloadPosition, client_static_s::downloadServer, ERR_DROP, dlhandle_s::file, dlhandle_s::filePath, FS_Gamedir(), FS_RemoveFile(), FS_RenameFile(), FS_RestartFilesystem(), handleCount, HTTPDL_ABORT_HARD, HTTPDL_ABORT_NONE, HTTPDL_ABORT_SOFT, client_static_s::HTTPHandles, i, MAX_OSPATH, multi, pendingCount, Q_streq, dlhandle_s::queueEntry, dlqueue_s::state, client_static_s::state, and dlqueue_s::ufoPath.

Referenced by CL_RunHTTPDownloads().

static dlhandle_t* CL_GetFreeDLHandle ( void )

static

Find a free download handle to start another queue entry on.

Definition at line 271 of file cl_http.cpp.

References cls, DLQ_STATE_DONE, client_static_s::HTTPHandles, i, dlhandle_s::queueEntry, and dlqueue_s::state.

Referenced by CL_StartNextHTTPDownload().

void CL_HTTP_Cleanup ( void )

UFO is exiting or we're changing servers. Clean up.

Definition at line 532 of file cl_http.cpp.

References cls, dlhandle_s::curl, dlhandle_s::file, dlhandle_s::filePath, client_static_s::HTTPHandles, i, Mem_Free, multi, dlhandle_s::queueEntry, Sys_Remove(), and dlhandle_s::tempBuffer.

Referenced by CL_SetHTTPServer(), and CL_Shutdown().

static int CL_HTTP_Progress	(	void *	clientp,
		double	dltotal,
		double	dlnow,
		double	ultotal,
		double	ulnow
	)

static

libcurl callback to update progress info. Mainly just used as a way to cancel the transfer if required.

Definition at line 81 of file cl_http.cpp.

References abortDownloads, cls, client_static_s::downloadName, client_static_s::downloadPercent, client_static_s::downloadPosition, int(), dlhandle_s::position, Q_strncpyz(), dlhandle_s::queueEntry, and dlqueue_s::ufoPath.

Referenced by CL_StartHTTPDownload().

static void CL_ParseFileList ( dlhandle_t * dl )

static

A filelist is in memory, scan and validate it and queue up the files.

Definition at line 486 of file cl_http.cpp.

References CL_CheckAndQueueDownload(), cvar_s::integer, Mem_Free, and dlhandle_s::tempBuffer.

Referenced by CL_FinishHTTPDownload().

bool CL_PendingHTTPDownloads ( void )

See if we're still busy with some downloads. Called by precacher just before it loads the map since we could be downloading the map. If we're busy still, it'll wait and CL_FinishHTTPDownload will pick up from where it left.

Definition at line 328 of file cl_http.cpp.

References cls, client_static_s::downloadServer, handleCount, and pendingCount.

Referenced by CL_CanMultiplayerStart(), and CL_FinishHTTPDownload().

bool CL_QueueHTTPDownload ( const char * ufoPath )

Called from the precache check to queue a download.

See also: CL_CheckOrDownloadFile

Definition at line 286 of file cl_http.cpp.

References abortDownloads, BASEDIRNAME, CL_QueueHTTPDownload(), cls, Com_GetExtension(), Com_sprintf(), DLQ_STATE_NOT_STARTED, client_static_s::downloadQueue, client_static_s::downloadServer, cvar_s::integer, len, MAX_OSPATH, Mem_AllocType, dlqueue_s::next, pendingCount, Q_strcasecmp, Q_streq, Q_strncpyz(), dlqueue_s::state, and dlqueue_s::ufoPath.

Referenced by CL_CheckAndQueueDownload(), CL_CheckOrDownloadFile(), and CL_QueueHTTPDownload().

static void CL_ReVerifyHTTPQueue ( void )

static

A pk3 file just downloaded, let's see if we can remove some stuff from the queue which is in the .pk3.

Definition at line 515 of file cl_http.cpp.

References cls, DLQ_STATE_DONE, DLQ_STATE_NOT_STARTED, client_static_s::downloadQueue, FS_LoadFile(), dlqueue_s::next, and pendingCount.

Referenced by CL_FinishHTTPDownload().

void CL_RunHTTPDownloads ( void )

This calls curl_multi_perform do actually do stuff. Called every frame while connecting to minimise latency. Also starts new downloads if we're not doing the maximum already.