Changeset 74008 in vbox for trunk/include/iprt/cpp

Timestamp:

Aug 31, 2018 7:08:02 PM (7 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

124754

Message:

IPRT/rest: Deal (more) properly with 'null'. bugref:9167

File:

• trunk/include/iprt/cpp/restbase.h (modified) (6 diffs)

trunk/include/iprt/cpp/restbase.h

@@ -256 +256 @@
 /**
  * Abstract base class for REST data objects.
+ *
+ * The only information this keeps is the null indicator.
  */
 class RT_DECL_CLASS RTCRestObjectBase
@@ -261 +263 @@
 public:
     RTCRestObjectBase();
+    RTCRestObjectBase(RTCRestObjectBase const &a_rThat);
     virtual ~RTCRestObjectBase();
 
-    /** @todo Add some kind of state? */
+    /**
+     * Tests if the object is @a null.
+     * @returns true if null, false if not.
+     */
+    bool isNull(void) const { return m_fNullIndicator; };
+
+    /**
+     * Sets the object to @a null and fills it with defaults.
+     * @returns IPRT status code (from resetToDefault).
+     */
+    virtual int setNull(void);
+
+    /**
+     * Sets the object to not-null state (i.e. undoes setNull()).
+     * @remarks Only really important for strings.
+     */
+    virtual void setNotNull(void);
 
     /**
@@ -353 +372 @@
     /** Pointer to factory method. */
     typedef FNCREATEINSTANCE *PFNCREATEINSTANCE;
+
+
+protected:
+    /** Null indicator.
+     * @remarks The null values could be mapped onto C/C++ NULL pointer values,
+     *          with the consequence that all data members in objects and such would
+     *          have had to been allocated individually, even simple @a bool members.
+     *          Given that we're overly paranoid about heap allocations (std::bad_alloc),
+     *          it's more fitting to use a null indicator for us.
+     */
+    bool    m_fNullIndicator;
 };
 
@@ -559 +589 @@
     RTCRestString(const char *a_pszSrc);
     /** Safe copy assignment method. */
+    int assignCopy(RTCRestString const &a_rThat);
+    /** Safe copy assignment method. */
     int assignCopy(RTCString const &a_rThat);
     /** Safe copy assignment method. */
@@ -564 +596 @@
 
     /* Overridden methods: */
+    virtual int setNull(void) RT_OVERRIDE; /* (ambigious, so overrider it to make sure.) */
     virtual int resetToDefault() RT_OVERRIDE;
     virtual RTCRestOutputBase &serializeAsJson(RTCRestOutputBase &a_rDst) const RT_OVERRIDE;
@@ -1297 +1330 @@
 
     /* Overridden methods: */
+    virtual int setNull(void) RT_OVERRIDE;
     virtual int resetToDefault() RT_OVERRIDE;
     virtual RTCRestOutputBase &serializeAsJson(RTCRestOutputBase &a_rDst) const RT_OVERRIDE;