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Use a bitmask instead of an array of bools in the SDP UUID List matching algorithm to reduce the compiled code size and stack used.

Browse Source
pull/1469/head
Dean Camera 14 years ago
parent e621ab33be
commit 559af02204
2 changed files with 17 additions and 18 deletions
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33
Demos/Host/Incomplete/BluetoothHost/Lib/SDP.c
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@ -458,27 +458,20 @@ static void* SDP_GetAttributeValue(const ServiceAttributeTable_t* AttributeTable
static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs,
const ServiceAttributeTable_t* CurrAttributeTable)
{
bool UUIDMatch[TotalUUIDs];
/* Set all the match flags to false (not matched) before starting the search */
memset(UUIDMatch, false, sizeof(UUIDMatch));
const void* CurrAttribute;
uint16_t UUIDMatchFlags = 0;
/* Search through the current attribute table, checking each attribute value for UUID matches */
while ((CurrAttribute = pgm_read_ptr(&CurrAttributeTable->Data)) != NULL)
{
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, UUIDMatch, CurrAttribute);
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, &UUIDMatchFlags, CurrAttribute);
CurrAttributeTable++;
}
/* Determine how many UUID matches in the list we have found */
uint8_t UUIDMatches = 0;
for (uint8_t i = 0; i < TotalUUIDs; i++)
{
if (UUIDMatch[i])
UUIDMatches++;
}
uint8_t UUIDMatches;
for (UUIDMatches = 0; UUIDMatchFlags; UUIDMatches++)
UUIDMatchFlags &= (UUIDMatchFlags - 1);
/* If all UUIDs have been matched to the current service, return true */
return (UUIDMatches == TotalUUIDs);
@ -494,7 +487,7 @@ static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const ui
*
* \return True if all the UUIDs given in the UUID list appear in the given attribute table, false otherwise
*/
static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs, bool UUIDMatch[],
static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs, uint16_t* UUIDMatchFlags,
const void* CurrAttribute)
{
uint8_t CurrAttributeType = (pgm_read_byte(CurrAttribute) & ~0x07);
@ -502,16 +495,20 @@ static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_
/* Check the data type of the current attribute value - if UUID, compare, if Sequence, unwrap and recurse */
if (CurrAttributeType == SDP_DATATYPE_UUID)
{
uint16_t CurrUUIDMatchMask = (1 << 0);
/* Look for matches in the UUID list against the current attribute UUID value */
for (uint8_t i = 0; i < TotalUUIDs; i++)
{
/* Check if the current unmatched UUID is identical to the search UUID */
if (!(UUIDMatch[i]) && !(memcmp_P(UUIDList[i], (CurrAttribute + 1), UUID_SIZE_BYTES)))
if (!(*UUIDMatchFlags & CurrUUIDMatchMask) && !(memcmp_P(UUIDList[i], (CurrAttribute + 1), UUID_SIZE_BYTES)))
{
/* Indicate match found for the current attribute UUID and early-abort */
UUIDMatch[i] = true;
*UUIDMatchFlags |= CurrUUIDMatchMask;
break;
}
CurrUUIDMatchMask <<= 1;
}
}
else if (CurrAttributeType == SDP_DATATYPE_Sequence)
@ -527,8 +524,10 @@ static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_
uint8_t InnerHeaderSize;
uint16_t InnerSize = SDP_GetLocalAttributeContainerSize(CurrAttribute, &InnerHeaderSize);
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, UUIDMatch, CurrAttribute);
/* Recursively search of the next element in the sequence, trying to match UUIDs with the UUID list */
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, UUIDMatchFlags, CurrAttribute);
/* Skip to the next element in the sequence */
SequenceSize -= InnerHeaderSize + InnerSize;
CurrAttribute += InnerHeaderSize + InnerSize;
}

2
Demos/Host/Incomplete/BluetoothHost/Lib/SDP.h
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@ -218,7 +218,7 @@
static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs,
const ServiceAttributeTable_t* CurrAttributeTable);
static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs, bool UUIDMatch[],
static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs, uint16_t* UUIDMatchFlags,
const void* CurrAttribute);
static uint8_t SDP_GetAttributeList(uint16_t AttributeList[][2], const void** const CurrentParameter);

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