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Comment by uptown | Hacker News Reader

Can somebody help me understand this conversion?

Shard ID = (241294492511762325 >> 46) & 0xFFFF = 3429

Type ID = (241294492511762325 >> 36) & 0x3FF = 1

Local ID = (241294492511762325 >> 0) & 0xFFFFFFFFF = 7075733

bitwise operations.

241294492511762325 >> 46 means shift the binary form of number which is

  0000001101011001010000000001000000000000011010111111011110010101

to the right 46 spaces while replacing with 0s

  0000000000000000000000000000000000000000000000000000110101100101

0xFFFF is hex version of 1111111111111111 (note two missing bits he reserved for gold :D )

& 0xFFFF is doing a AND operation of the bits.

  0000110101100101
  1111111111111111
  ----------------
  0000110101100101

so 0000110101100101 in decimal is 3429

These are bit shift operations with a bitmask. Basically the ids are 64-bit and sections are reserved to identify the shard, type, and local id.