Commit 559af022 authored by Dean Camera's avatar Dean Camera
Browse files

Use a bitmask instead of an array of bools in the SDP UUID List matching...

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.
parent e621ab33
...@@ -458,27 +458,20 @@ static void* SDP_GetAttributeValue(const ServiceAttributeTable_t* AttributeTable ...@@ -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, static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs,
const ServiceAttributeTable_t* CurrAttributeTable) 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; const void* CurrAttribute;
uint16_t UUIDMatchFlags = 0;
/* Search through the current attribute table, checking each attribute value for UUID matches */ /* Search through the current attribute table, checking each attribute value for UUID matches */
while ((CurrAttribute = pgm_read_ptr(&CurrAttributeTable->Data)) != NULL) while ((CurrAttribute = pgm_read_ptr(&CurrAttributeTable->Data)) != NULL)
{ {
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, UUIDMatch, CurrAttribute); SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, &UUIDMatchFlags, CurrAttribute);
CurrAttributeTable++; CurrAttributeTable++;
} }
/* Determine how many UUID matches in the list we have found */ /* Determine how many UUID matches in the list we have found */
uint8_t UUIDMatches = 0; uint8_t UUIDMatches;
for (uint8_t i = 0; i < TotalUUIDs; i++) for (UUIDMatches = 0; UUIDMatchFlags; UUIDMatches++)
{ UUIDMatchFlags &= (UUIDMatchFlags - 1);
if (UUIDMatch[i])
UUIDMatches++;
}
/* If all UUIDs have been matched to the current service, return true */ /* If all UUIDs have been matched to the current service, return true */
return (UUIDMatches == TotalUUIDs); return (UUIDMatches == TotalUUIDs);
...@@ -494,7 +487,7 @@ static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const ui ...@@ -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 * \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) const void* CurrAttribute)
{ {
uint8_t CurrAttributeType = (pgm_read_byte(CurrAttribute) & ~0x07); uint8_t CurrAttributeType = (pgm_read_byte(CurrAttribute) & ~0x07);
...@@ -502,16 +495,20 @@ static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_ ...@@ -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 */ /* Check the data type of the current attribute value - if UUID, compare, if Sequence, unwrap and recurse */
if (CurrAttributeType == SDP_DATATYPE_UUID) if (CurrAttributeType == SDP_DATATYPE_UUID)
{ {
uint16_t CurrUUIDMatchMask = (1 << 0);
/* Look for matches in the UUID list against the current attribute UUID value */ /* Look for matches in the UUID list against the current attribute UUID value */
for (uint8_t i = 0; i < TotalUUIDs; i++) for (uint8_t i = 0; i < TotalUUIDs; i++)
{ {
/* Check if the current unmatched UUID is identical to the search UUID */ /* 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 */ /* Indicate match found for the current attribute UUID and early-abort */
UUIDMatch[i] = true; *UUIDMatchFlags |= CurrUUIDMatchMask;
break; break;
} }
CurrUUIDMatchMask <<= 1;
} }
} }
else if (CurrAttributeType == SDP_DATATYPE_Sequence) else if (CurrAttributeType == SDP_DATATYPE_Sequence)
...@@ -527,8 +524,10 @@ static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_ ...@@ -527,8 +524,10 @@ static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_
uint8_t InnerHeaderSize; uint8_t InnerHeaderSize;
uint16_t InnerSize = SDP_GetLocalAttributeContainerSize(CurrAttribute, &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; SequenceSize -= InnerHeaderSize + InnerSize;
CurrAttribute += InnerHeaderSize + InnerSize; CurrAttribute += InnerHeaderSize + InnerSize;
} }
......
...@@ -218,7 +218,7 @@ ...@@ -218,7 +218,7 @@
static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs, static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES], const uint8_t TotalUUIDs,
const ServiceAttributeTable_t* CurrAttributeTable); 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); const void* CurrAttribute);
static uint8_t SDP_GetAttributeList(uint16_t AttributeList[][2], const void** const CurrentParameter); static uint8_t SDP_GetAttributeList(uint16_t AttributeList[][2], const void** const CurrentParameter);
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment