Function MaxEncodedLen

s2/encode.go:389–418

MaxEncodedLen returns the maximum length of a snappy block, given its uncompressed length. It will return a negative value if srcLen is too large to encode. 32 bit platforms will have lower thresholds for rejecting big content.

(srcLen int)

// It will return a negative value if srcLen is too large to encode.
// 32 bit platforms will have lower thresholds for rejecting big content.
func MaxEncodedLen(srcLen int) int {
	n := uint64(srcLen)
	if intReduction == 1 {
		// 32 bits
		if n > math.MaxInt32 {
			// Also includes negative.
			return -1
		}
	} else if n > 0xffffffff {
		// 64 bits
		// Also includes negative.
		return -1
	}
	// Size of the varint encoded block size.
	n = n + uint64((bits.Len64(n)+7)/7)

	// Add maximum size of encoding block as literals.
	n += uint64(literalExtraSize(int64(srcLen)))
	if intReduction == 1 {
		// 32 bits
		if n > math.MaxInt32 {
			return -1
		}
	} else if n > 0xffffffff {
		// 64 bits
		// Also includes negative.
		return -1
	}
	return int(n)
}