Method and apparatus for enhanced hashing
View Patent ↗A search key lookup system including a hash table having a plurality of entries and a function generator is disclosed. The function generator can be coupled to the hash table and configured to receive a key and to provide a first function and a second function. The first function can be a Cyclic Redundancy Code (CRC) type function and the second function can be an Error Checking and Correcting (ECC) type function. Further, an address of the table can include a concatenation of the results of the CRC and the ECC type functions.
1. A search key lookup system for moving packets of information in networking systems from one of a number of input ports to one or more output ports, comprising:
a tangible computer readable medium including a table having a plurality of entries; and
a function generator in communication with the table and configured to receive a key and to provide a first function and a second function, wherein an address of the table includes outputs of the first function and the second function;
wherein each of the plurality of entries includes at least one field;
wherein the at least one field includes a key field and an attribute field;
wherein the key includes information extracted from a packet header;
wherein the attribute field is configured to store a port number; and
wherein the function generator includes a hash function;
wherein the address of the table includes a concatenation of outputs of the first function and the second function.
2. The search key lookup system of claim 1 , wherein:
the at least one field consists of a key field and an attribute field.
3. The search key lookup system of claim 1 , wherein:
the address of the table includes information associated with the key.
4. The search key lookup system of claim 3 , wherein:
the table is substantially without a field configured for storing the information associated with the key.
5. The search key lookup system of claim 1 , wherein:
the first function includes a Cyclic Redundancy Code (CRC) type function.
6. The search key lookup system of claim 5 , wherein:
the second function includes an Error Checking and Correcting (FCC) type function.
7. The search key lookup system of claim 1 , wherein:
the table includes a hash table.
8. The search key lookup system of claim 1 , wherein:
a number of bits of the address is substantially less than a number of bits of the key.
9. The search key lookup system of claim 1 , wherein the concatenation includes a concatenation of FCC and CRC function outputs.
10. The search key lookup system of claim 1 , wherein an FCC function is embedded in the address of the table.