davsearch.c

来自「FDI Intel开发的FLASH文件系统,功能很强大」· C语言 代码 · 共 1,358 行 · 第 1/4 页

            if (objHeaderRead)
            {
               if(
                  (aSrchInfoPtr->HeaderPtr->OHdr.NameSize == aCompareInfoPtr->NameSize) &&
                  (FHDR_GetAllocationStatus(&(aSrchInfoPtr->HeaderPtr->FHdr)) != HDR_ALLOC_INVALID)
                 )
               {
                  found = 1;
                  /* Do the comparison */
                  for (ii=0; ii<aCompareInfoPtr->NameSize; ii++)
                  {
                     if (aSrchInfoPtr->HeaderPtr->OHdr.Name[ii] != ((UINT8*)aCompareInfoPtr->NamePtr)[ii])
                     {
                        found = 0;
                        break;
                     }
                  }
               }
               else
               {
                  found = 0;
               }
            }
            else
            {
               found = 0;
            }
         break;

         case SEARCH_ByObjectAddress:
            if (
               ((FHDR_CalcObjectHandle(&(aSrchInfoPtr->HeaderPtr->FHdr)) + OHDR_CalcHeaderSize()) == aCompareInfoPtr->CompareValue)
               )
            {
               found = 1;
            }
            break;
         case SEARCH_ByObjectHeaderAddress:
            if (
               (FHDR_CalcObjectHandle(&(aSrchInfoPtr->HeaderPtr->FHdr)) == aCompareInfoPtr->CompareValue)
               )
            {
               found = 1;
            }
         break;
      
         case SEARCH_ByNextValidParaObject:     
            if (
                (FHDR_GetAllocationStatus(&(aSrchInfoPtr->HeaderPtr->FHdr)) == HDR_ALLOC_VALID) &&
                (FHDR_GetHeaderStatus(&(aSrchInfoPtr->HeaderPtr->FHdr))     == HDR_HEADER_VALID) &&
                (FHDR_IsParaObject(&(aSrchInfoPtr->HeaderPtr->FHdr)))
               )
            {
               found = 1;
            }
            break;
         default: {};
      }
   }
   else /* header is absorbed and doesn't point to anything */
   {
      found = 0;
   }
   
   *aFoundValPtr = found;
   return status;
}


/*#################################################################
### SEARCH_GetNextHeaderHandle
###
### DESCRIPTION:
###   This function provides the search routines with a fast method
###   of scanning the header table.  It only returns the fixed header,
###   header address, object address, and object size.
###   The HDR_ReadFullHeader function
###   can then be used along with the handle of the header, to
###   read the entire header.  This loads the aSrchInfoPtr 
###   header(partial), object size, and header address.
###
### PARAMETERS:
###   aSrchInfoPtr  - Structure containing search information.
###      IN:  - CurrObj.HeaderAddress references a valid header 
###              and value of 0 will start the search from the 
###              beginning of the header table.
###           - HeaderPtr points to a valid header for temporary 
###              use.
###
###      OUT: - CurrObj.HeaderAddress will reference the header 
###              address of the next header matching the type of 
###              search performed.
###           - CurrObj.ObjectSize will contain the size, in bytes,
###              of the object and the object header combined.
###           - HeaderPtr will contain the contents of the
###              minimum information necessary to locate any
###              one object in memory space.
###
### RETURNS:
###   When this function passes with no errors a value of 0 is
###   returned otherwise, it returns a status of type ERR_CODE.
###
###   ERR_NONE       - Entry was found and the aSrchInfoPtr 
###                   contains valid header information.
###
###   ERR_NO_MORE_ENTRIES - The entry was not found after searching
###                   the entire header table.
###*/
ERR_CODE SEARCH_GetNextHeaderHandle(SEARCH_SearchInfoPtr        aSrchInfoPtr,
                                    SEARCH_SpecialConditionEnum aSpecialCondition,
                                    BOOLEAN                     restart)
{
ERR_CODE   status     = ERR_NONE;
FDI_Handle nextHeader = FDI_InvalidObjAddress; /* DAV - init to invalid value */

   /* Set start_addr to either the top of Flash memory or to *handle_ptr */
   if ((aSrchInfoPtr->CurrObj.HeaderAddress == 0) ||
       (aSpecialCondition == SEARCH_StartAtCurrent))
   {
      if (aSrchInfoPtr->CurrObj.HeaderAddress == 0)
      {
         /* Read the first header entry. */
         nextHeader = aSrchInfoPtr->CurrObj.HeaderAddress = 
                                                DAV_MEM_FirstHeaderAddr;
      }
   }
   else
   {
      if (aSpecialCondition == SEARCH_Normal)
      {
         nextHeader = SEARCH_CalcNextHdrAddr(aSrchInfoPtr->CurrObj.HeaderAddress);
      }
   }
   
   if (aSpecialCondition == SEARCH_StartAtCurrent)
   {
      nextHeader = aSrchInfoPtr->CurrObj.HeaderAddress;
   }
   
   /* Read the header */
   status = FHDR_ReadFixedHeader(nextHeader, &(aSrchInfoPtr->HeaderPtr->FHdr), restart);
   ExitOnError(status);  

   /* Calculate Next Header's Header Base Address */
   aSrchInfoPtr->CurrObj.HeaderAddress = nextHeader;
   
   if (FHDR_GetHeaderStatus(&(aSrchInfoPtr->HeaderPtr->FHdr)) == HDR_HEADER_UNUSED)
   {
      status = ERR_NO_MORE_ENTRIES;
      ExitOnError(status);
   }

   /* Authenticate that the header is in a good state if required */
   if (FHDR_AuthenticateHeader(&(aSrchInfoPtr->HeaderPtr->FHdr)) != HDR_STATUS_Authentic)
   {
      status = ERR_PARAM;
      ExitOnError(status);
   }
   else
   {
      if (FHDR_GetAbsorbStatus(&(aSrchInfoPtr->HeaderPtr->FHdr)) != HDR_ABSORBED)
      {
         /* Store object address */
         aSrchInfoPtr->CurrObj.ObjectAddress = 
            FHDR_CalcObjectHandle(&(aSrchInfoPtr->HeaderPtr->FHdr));

         /* Store object size */
         aSrchInfoPtr->CurrObj.ObjectSize = 
            FHDR_CalcObjectSize(&(aSrchInfoPtr->HeaderPtr->FHdr));
      }
   }

   return status;
}
                
/*#################################################################
  ### SEARCH_GetNextHeader
  ###
  ### DESCRIPTION:
  ###   This function will return information about the next object
  ###   in the header table, calculate the address of the object and 
  ###   keep track of the search state using the aSrchInfoPtr.  
  ###   Header information is returned in its raw state.
  ###
  ###   The start point is determined by the HeaderAddress in the
  ###   aSrchInfoPtr.  This value can be from a previous call
  ###   or from previous knowledge of the location of a particular
  ###   header entry.  The next object that matches (depends on
  ###   search method) will be returned in the aSrchInfoPtr.  
  ###   The restart parameter is used to start from and includes the 
  ###   first object in the header table without knowing the address
  ###   of the first entry.
  ###
  ### PARAMETERS:
  ###   aSrchInfoPtr - Structure containing detailed information
  ###                     about the desired object.
  ###    IN:  The CurrObj.HeaderAddress field must contain a valid
  ###         start address to begin searching from.  A value of 0
  ###         will start the search from the beginning of the header
  ###         table.
  ###         
  ###    OUT: The state of the search will be completely stored
  ###         in this structure upon return.  This will allow
  ###         the caller to return to a previous search state
  ###         no matter what other functions might have called
  ###         it (this function is re-entrant).
  ### 
  ###         All information about an object is returned including
  ###         the entire contents of the header (minus name).  The
  ###         HDR_ReadFullHeader function must be used to get the
  ###         name and any other fields that are not essential to
  ###         the search algorithm.
  ###         
  ###   aCompareMethod  - Search for the next object with the 
  ###                     following qualities:
  ###                     
  ###      SEARCH_ByNextObject       //Return next object in the header 
  ###                             // table.
  ###      SEARCH_ByNextValidObject  //Return the next valid object in 
  ###                             // the header table.  
  ###      SEARCH_ByNextParaObject   //Return next para object in the 
  ###                             // header table.
  ###      SEARCH_ByNextPageObject   //Return next page object in the 
  ###                             // header table.
  ###      SEARCH_ByValidType        //Return the next valid object with 
  ###                             // the specified type.
  ###      SEARCH_ByHeaderAddress    //Return the next object that matches the
  ###                             // specified header address (fast search).
  ###      SEARCH_ByTypeOnly         //Return the next object of the specified 
  ###                             // type.
  ###      SEARCH_ByNameType         //Return the next object with the specified 
  ###                             // name + type.
  ###      SEARCH_ByName             //Return the next object with the specified 
  ###                             // name.
  ###
  ###   compare_value   - Used to compare header values based
  ###                     on the method chosen.
  ###                     e.g. Using the SearchByHeaderAddress, 
  ###                          the calling function would place 
  ###                          the desired header address in the 
  ###                          compare_value parameter.
  ###
  ### RETURNS:
  ###   When this function passes with no errors a value of 0 is
  ###   returned otherwise, it returns a status of type ERR_CODE.
  ###
  ###   ERR_NONE       - Entry was found and the aSrchInfoPtr 
  ###                   contains valid header information.
  ###
  ###   ERR_NO_MORE_ENTRIES - The entry was not found after searching
  ###                   the entire header table.
  ###*/
ERR_CODE SEARCH_GetNextHeader(SEARCH_SearchInfoPtr    aSrchInfoPtr,
                              SEARCH_SearchMethodEnum aCompareMethod, 
                              SEARCH_CompareInfoPtr   aCompareInfoPtr,
                              BOOLEAN                 restart)
{                               
ERR_CODE status = ERR_NONE;
UINT8    foundVal = 0;

   while (status != ERR_NO_MORE_ENTRIES)
   {
      status = SEARCH_GetNextHeaderHandle(aSrchInfoPtr, SEARCH_Normal, restart);

      if (!status)
      {
         /* Since we need data from the obj header, the obj header was also read */
         status = IsFound(aSrchInfoPtr, aCompareMethod, aCompareInfoPtr,
                             &foundVal, restart);
         if(status)
         {
            return(status);
         }

         if (foundVal)
         {
            return ERR_NONE;
         }
      }
   }
   
   return status;
}

/*#################################################################
  ### SEARCH_CalcNextHdrAddr
  ### 
  ### DESCRIPTION:
  ###   This function will take the current header handle and use it to
  ###   calculate the address of the next header just below it in
  ###   paragraph space.
  ### 
  ### PARAMETERS:
  ###   aCurrentHeaderHandle - Address of the current header.
  ###   nextHeaderHandle - Ptr to address of the next header.
  ### 
  ### RETURNS:
  ###   Handle to next header.
  ###*/
FDI_Handle SEARCH_CalcNextHdrAddr(FDI_Handle aCurrentHeaderHandle)
{
   return (aCurrentHeaderHandle - FHDR_CalcHeaderSize());
}

/*#################################################################
  ### SEARCH_CalcFirstUserObjectHdrAddr
  ### 
  ### DESCRIPTION:
  ###   This function will compute the address of the header of
  ###   the first user object, dirty chunk, or free chunk that
  ###   exists in page space.
  ### 
  ### PARAMETERS:
  ###   aCurrentHeaderHandle - Address of the current header.
  ###   aNextHeaderHandlePtr - Ptr to address of the next header.
  ### 
  ### RETURNS:
  ###   Error status.
  ###*/
ERR_CODE SEARCH_CalcFirstUserObjectHdrAddr(FDI_HandlePtr aHandlePtr)
{
ERR_CODE                  status = ERR_NONE;
FDI_Handle                currHeaderHandle = DAV_MEM_FirstHeaderAddr;
FDI_Handle                lastHeaderHandle = DAV_MEM_FirstHeaderAddr;
HDR_FixedHeader           currHeader;
UINT32                    currOffset = HDR_INDEX_OFFSET_UNUSED;
UINT32                    candidateOffset = 0;

   HDR_InitHeaderAttr1(currHeader.Attr1);
   HDR_InitHeaderAttr2(currHeader.Attr2);

   do
   {
      status = FHDR_ReadFixedHeader(currHeaderHandle, &currHeader, FALSE);
      /* if the header points to a real user object, dirty chunk, or free chunk in page space */
      if (
            (status == ERR_NONE) &&
            (FHDR_GetHeaderStatus(&currHeader) == HDR_HEADER_VALID) && 
            (FHDR_GetAbsorbStatus(&currHeader) != HDR_ABSORBED) &&