[libvirt] [PATCH] esx: Map the .vmx annotation to the domain XML description

[Matthias Bolte]

2010/8/27 Eric Blake <eblake at redhat.com>:
> On 08/27/2010 10:31 AM, Matthias Bolte wrote:
>>
>> +    char *annotation = NULL;
>> +    char *tmp;
>> +    int length;
>
> s/int/size_t/
>
>>      int controller;
>>      int bus;
>>      int port;
>> @@ -947,6 +950,33 @@ esxVMX_ParseConfig(esxVMX_Context *ctx, virCapsPtr
>> caps, const char *vmx,
>>          goto cleanup;
>>      }
>>
>> +    /* vmx:annotation ->  def:description */
>> +    if (esxUtil_GetConfigString(conf, "annotation",&def->description,
>> +                                true)<  0) {
>> +        goto cleanup;
>> +    }
>> +
>> +    /* Replace '|22' with '"' and '|7C' with '|' */
>
> Looking at that comment, it looks like |xx for any two arbitrary hex digits
> is a valid escape sequence.  While you only need to be strict in what you
> generate (escapes only for the problematic characters that can't be sent
> literally), should you be liberal in what you accept (all possible | escapes
> for any byte, even if the byte could have been sent literally)?
>
>> +    if (def->description != NULL) {
>> +        length = strlen(def->description) + 1;
>> +        tmp = def->description;
>> +
>> +        while (*tmp != '\0') {
>> +            if (STRPREFIX(tmp, "|22")) {
>> +                *tmp = '"';
>> +                memmove(tmp + 1, tmp + 3, length - 3);
>> +                length -= 2;
>
> Hmm - this scales quadratically (that is, decoding a sequence of 20 "|22"
> requires 19 memmoves, totaling 190 sequence relocations).  I would prefer a
> linear rewrite - have two pointers, one that tracks where you are reading,
> and one that tracks where you are writing (you already did this on the loop
> adding the escapes).  Then, on every iteration, the read pointer may advance
> multiple positions, but the write pointer advances only one, and you don't
> need any memmoves.

In v2 (attached) I made this unescape all |XX and removed the memmoves.

To convert XX to the actual char I moved hextobin (used internally by
virUUIDParse) to util.c and used it here. The move is done in a
separate patch (attached).

Matthias
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