#include "device_properties.h"

Public Types
enum	ImageQualityPreference { kImageQualityDefault, kImageQualityLow, kImageQualityMedium, kImageQualityHigh }

Public Member Functions
	DeviceProperties (UserAgentMatcher *matcher)

void	SetUserAgent (const StringPiece &user_agent_string)

void	ParseRequestHeaders (const RequestHeaders &request_headers)

bool	SupportsImageInlining () const

bool	SupportsLazyloadImages () const

bool	SupportsCriticalCss () const

bool	SupportsCriticalImagesBeacon () const

bool	SupportsJsDefer (bool enable_mobile) const

bool	SupportsWebpInPlace () const

bool	SupportsWebpRewrittenUrls () const

bool	SupportsWebpLosslessAlpha () const

bool	SupportsWebpAnimated () const

bool	IsBot () const

bool	AcceptsGzip () const

UserAgentMatcher::DeviceType	GetDeviceType () const

bool	IsMobile () const

bool	IsTablet () const

bool	ForbidWebpInlining () const

bool	RequestsSaveData () const

bool	HasViaHeader () const

Static Public Attributes
static const int	kMediumScreenWidthThreshold = 720

static const int	kLargeScreenWidthThreshold = 1500

Friends
class	ImageRewriteTest

class	RequestProperties

Detailed Description

This class keeps track of the device properties of the client, which are for the most part learned from the UserAgent string.

Member Enumeration Documentation

enum net_instaweb::DeviceProperties::ImageQualityPreference

Enumerator
kImageQualityDefault	Server uses its own default image quality.
kImageQualityLow	The request asks for low image quality.
kImageQualityMedium	The request asks for medium image quality.
kImageQualityHigh	The request asks for high image quality.

Member Function Documentation

void net_instaweb::DeviceProperties::ParseRequestHeaders ( const RequestHeaders & request_headers )

Set device-based properties that are capture in the request headers (eg. the Accept: header).

bool net_instaweb::DeviceProperties::SupportsWebpInPlace ( ) const

SupportsWebpInPlace indicates we saw an Accept: image/webp header, and can rewrite the request in place (using Vary: accept in the result headers, etc.).

bool net_instaweb::DeviceProperties::SupportsWebpRewrittenUrls ( ) const

SupportsWebpRewrittenUrls indicates that the device can handle webp so long as the url changes - either we know this based on user agent, or we got an Accept header. We can't tell a proxy cache to distinguish this case using Vary: accept in the result headers, as we can't guarantee we'll see such a header, ever. So we need to Vary: user-agent or cache-control: private, and thus restrict it to rewritten urls.

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

net/instaweb/rewriter/public/device_properties.h

Public Types

Public Member Functions

Static Public Attributes

Friends

Detailed Description

Member Enumeration Documentation

Member Function Documentation