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      1 /*
      2  * Copyright 2013 Google, Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 
      9 #ifndef SkRTConf_DEFINED
     10 #define SkRTConf_DEFINED
     11 
     12 #include "SkString.h"
     13 #include "SkStream.h"
     14 
     15 #include "SkTDict.h"
     16 #include "SkTArray.h"
     17 
     18 /** \class SkRTConfBase
     19     Non-templated base class for the runtime configs
     20 */
     21 
     22 class SkRTConfBase {
     23 public:
     24     SkRTConfBase(const char *name) : fName(name) {}
     25     virtual ~SkRTConfBase() {}
     26     virtual const char *getName() const { return fName.c_str(); }
     27     virtual bool isDefault() const = 0;
     28     virtual void print(SkWStream *o) const = 0;
     29     virtual bool equals(const SkRTConfBase *conf) const = 0;
     30 protected:
     31     SkString fName;
     32 };
     33 
     34 /** \class SkRTConf
     35     A class to provide runtime configurability.
     36 */
     37 template<typename T> class SkRTConf: public SkRTConfBase {
     38 public:
     39     SkRTConf(const char *name, const T &defaultValue, const char *description);
     40     operator const T&() const { return fValue; }
     41     void print(SkWStream *o) const;
     42     bool equals(const SkRTConfBase *conf) const;
     43     bool isDefault() const { return fDefault == fValue; }
     44     void set(const T& value) { fValue = value; }
     45 protected:
     46     void doPrint(char *s) const;
     47 
     48     T        fValue;
     49     T        fDefault;
     50     SkString fDescription;
     51 };
     52 
     53 #ifdef SK_DEVELOPER
     54 #define SK_CONF_DECLARE(confType, varName, confName, defaultValue, description) static SkRTConf<confType> varName(confName, defaultValue, description)
     55 #define SK_CONF_SET(confname, value) \
     56     skRTConfRegistry().set(confname, value, true)
     57 /* SK_CONF_TRY_SET() is like SK_CONF_SET(), but doesn't complain if
     58    confname can't be found.  This is useful if the SK_CONF_DECLARE is
     59    inside a source file whose linkage is dependent on the system. */
     60 #define SK_CONF_TRY_SET(confname, value) \
     61     skRTConfRegistry().set(confname, value, false)
     62 #else
     63 #define SK_CONF_DECLARE(confType, varName, confName, defaultValue, description) static confType varName = defaultValue
     64 #define SK_CONF_SET(confname, value) (void) confname, (void) value
     65 #define SK_CONF_TRY_SET(confname, value) (void) confname, (void) value
     66 #endif
     67 
     68 /** \class SkRTConfRegistry
     69     A class that maintains a systemwide registry of all runtime configuration
     70     parameters.  Mainly used for printing them out and handling multiply-defined
     71     knobs.
     72 */
     73 
     74 class SkRTConfRegistry {
     75 public:
     76     SkRTConfRegistry();
     77     ~SkRTConfRegistry();
     78     void printAll(const char *fname = NULL) const;
     79     bool hasNonDefault() const;
     80     void printNonDefault(const char *fname = NULL) const;
     81     const char *configFileLocation() const;
     82     void possiblyDumpFile() const;
     83     void validate() const;
     84     template <typename T> void set(const char *confname,
     85                                    T value,
     86                                    bool warnIfNotFound = true);
     87 #ifdef SK_SUPPORT_UNITTEST
     88     static void UnitTest();
     89 #endif
     90 private:
     91     template<typename T> friend class SkRTConf;
     92 
     93     void registerConf(SkRTConfBase *conf);
     94     template <typename T> bool parse(const char *name, T* value);
     95 
     96     SkTDArray<SkString *> fConfigFileKeys, fConfigFileValues;
     97     typedef SkTDict< SkTDArray<SkRTConfBase *> * > ConfMap;
     98     ConfMap fConfs;
     99 #ifdef SK_SUPPORT_UNITTEST
    100     SkRTConfRegistry(bool);
    101 #endif
    102 };
    103 
    104 // our singleton registry
    105 
    106 SkRTConfRegistry &skRTConfRegistry();
    107 
    108 template<typename T>
    109 SkRTConf<T>::SkRTConf(const char *name, const T &defaultValue, const char *description)
    110     : SkRTConfBase(name)
    111     , fValue(defaultValue)
    112     , fDefault(defaultValue)
    113     , fDescription(description) {
    114 
    115     T value;
    116     if (skRTConfRegistry().parse(fName.c_str(), &value)) {
    117         fValue = value;
    118     }
    119     skRTConfRegistry().registerConf(this);
    120 }
    121 
    122 template<typename T>
    123 void SkRTConf<T>::print(SkWStream *o) const {
    124     char outline[200]; // should be ok because we specify a max. width for everything here.
    125     char *outptr;
    126     if (strlen(getName()) >= 30) {
    127         o->writeText(getName());
    128         o->writeText(" ");
    129         outptr = &(outline[0]);
    130     } else {
    131         sprintf(outline, "%-30.30s", getName());
    132         outptr = &(outline[30]);
    133     }
    134 
    135     doPrint(outptr);
    136     sprintf(outptr+30, " %.128s", fDescription.c_str());
    137     for (size_t i = strlen(outline); i --> 0 && ' ' == outline[i];) {
    138         outline[i] = '\0';
    139     }
    140     o->writeText(outline);
    141 }
    142 
    143 template<typename T>
    144 void SkRTConf<T>::doPrint(char *s) const {
    145     sprintf(s, "%-30.30s", "How do I print myself??");
    146 }
    147 
    148 template<> inline void SkRTConf<bool>::doPrint(char *s) const {
    149     char tmp[30];
    150     sprintf(tmp, "%s # [%s]", fValue ? "true" : "false", fDefault ? "true" : "false");
    151     sprintf(s, "%-30.30s", tmp);
    152 }
    153 
    154 template<> inline void SkRTConf<int>::doPrint(char *s) const {
    155     char tmp[30];
    156     sprintf(tmp, "%d # [%d]", fValue, fDefault);
    157     sprintf(s, "%-30.30s", tmp);
    158 }
    159 
    160 template<> inline void SkRTConf<unsigned int>::doPrint(char *s) const {
    161     char tmp[30];
    162     sprintf(tmp, "%u # [%u]", fValue, fDefault);
    163     sprintf(s, "%-30.30s", tmp);
    164 }
    165 
    166 template<> inline void SkRTConf<float>::doPrint(char *s) const {
    167     char tmp[30];
    168     sprintf(tmp, "%6.6f # [%6.6f]", fValue, fDefault);
    169     sprintf(s, "%-30.30s", tmp);
    170 }
    171 
    172 template<> inline void SkRTConf<double>::doPrint(char *s) const {
    173     char tmp[30];
    174     sprintf(tmp, "%6.6f # [%6.6f]", fValue, fDefault);
    175     sprintf(s, "%-30.30s", tmp);
    176 }
    177 
    178 template<> inline void SkRTConf<const char *>::doPrint(char *s) const {
    179     char tmp[30];
    180     sprintf(tmp, "%s # [%s]", fValue, fDefault);
    181     sprintf(s, "%-30.30s", tmp);
    182 }
    183 
    184 template<typename T>
    185 bool SkRTConf<T>::equals(const SkRTConfBase *conf) const {
    186     // static_cast here is okay because there's only one kind of child class.
    187     const SkRTConf<T> *child_pointer = static_cast<const SkRTConf<T> *>(conf);
    188     return child_pointer &&
    189            fName == child_pointer->fName &&
    190            fDescription == child_pointer->fDescription &&
    191            fValue == child_pointer->fValue &&
    192            fDefault == child_pointer->fDefault;
    193 }
    194 
    195 #endif
    196