dns.wire

writer:name(domain)

Write a DNS name with compression

Writes a DNS domain name to the wire, using compression pointers for previously-seen suffixes. The domain should include a trailing dot (e.g. "example.com."). If omitted, one is appended.

The writer maintains a compression table mapping FQDN suffixes to their 0-based wire offsets. When a suffix has been seen before, a 2-byte pointer is emitted instead of repeating the labels.

Validation:

• Labels longer than 63 bytes cause an error
• Total wire-format name length exceeding 255 bytes causes an error
• Suffixes at offsets >= 16384 are not eligible for compression (14-bit pointer field limit)