Fix ziplist prevlen encoding description. See #4705.

This commit is contained in:
antirez 2018-02-23 12:19:30 +01:00
parent ffde73c57d
commit 813960dbdd

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@ -53,20 +53,20 @@
* <prevlen> <encoding>
*
* The length of the previous entry, <prevlen>, is encoded in the following way:
* If this length is smaller than 255 bytes, it will only consume a single
* If this length is smaller than 254 bytes, it will only consume a single
* byte representing the length as an unsinged 8 bit integer. When the length
* is greater than or equal to 255, it will consume 5 bytes. The first byte is
* set to 255 (FF) to indicate a larger value is following. The remaining 4
* is greater than or equal to 254, it will consume 5 bytes. The first byte is
* set to 254 (FE) to indicate a larger value is following. The remaining 4
* bytes take the length of the previous entry as value.
*
* So practically an entry is encoded in the following way:
*
* <prevlen from 0 to 254> <encoding> <entry>
* <prevlen from 0 to 253> <encoding> <entry>
*
* Or alternatively if the previous entry length is greater than 254 bytes
* Or alternatively if the previous entry length is greater than 253 bytes
* the following encoding is used:
*
* 0xFF <4 bytes unsigned little endian prevlen> <encoding> <entry>
* 0xFE <4 bytes unsigned little endian prevlen> <encoding> <entry>
*
* The encoding field of the entry depends on the content of the
* entry. When the entry is a string, the first 2 bits of the encoding first