[postgis-devel] Re: [postgis-users] how to identify the_geom that cause : RelateOperation called withLWGEOMCOLLECTION type

[Kevin Neufeld]

Yup, that's makes sense ... it's similar to what I have in errorIfGeometryCollection.

Doing a little testing, however, I'm not clear on what you were expecting to see based on certain inputs - my expected 
results don't match the function output.  I put the function in a little test.c file to test the method where:


char* str = "abcdefghijklmnopqrstuvwxyz";

// Assuming 0-based indexing
lwmessage_truncate(str, 0, strlen(str)-1, 26, 0);
expected: "abcdefghijklmnopqrstuvwxyz"
output:   "abcdefghijklmnopqrstuvwxy"

lwmessage_truncate(str, 0, strlen(str)-1, 26, 1);
expected: "abcdefghijklmnopqrstuvwxyz"
output:   "abcdefghijklmnopqrstuvwxy"

lwmessage_truncate(str, 0, strlen(str)-1, 25, 0);
expected: "...efghijklmnopqrstuvwxyz"
output:   "abcdefghijklmnopqrstuvwxy"

lwmessage_truncate(str, 0, strlen(str)-1, 25, 1);
expected: "abcdefghijklmnopqrstuv..."
output:   "abcdefghijklmnopqrstuvwxy"

lwmessage_truncate(str, 0, strlen(str)-1, 10, 1);
expected: "abcdefg..."
output:   "abcdefg..."

lwmessage_truncate(str, 2, strlen(str)-1, 10, 1);
expected: "cdefghi..."
output:   "abcdefg..."

lwmessage_truncate(str, 4, strlen(str)-1, 10, 1);
expected: "efghijk..."
output:   "abcdefg..."

lwmessage_truncate(str, 0, strlen(str)-1, 10, 0);
expected: "...tuvwxyz"
output:   "...stuvwxy"

lwmessage_truncate(str, 0, strlen(str)-3, 10, 0);
expected: "...rstuvwx"
output:   "...qrstuvw"

lwmessage_truncate(str, 0, strlen(str)-5, 10, 0);
expected: "...pqrstuv"
output:   "...opqrstu"

lwmessage_truncate(str, 0, strlen(str)-1, 4, 1);
expected: "a..."
output:   "a..."

lwmessage_truncate(str, 0, strlen(str)-1, 3, 1);
expected: "a.."
output:   "..."

lwmessage_truncate(str, 0, strlen(str)-1, 2, 1);
expected: "a."
output:   "abcdefghijklmnopqrstuvwxyz..."
*** glibc detected *** free(): invalid next size (fast): 0x08b88028 ***
Aborted


Am I using it correctly?
Cheers,
Kevin



Mark Cave-Ayland wrote:
> Kevin Neufeld wrote:
> 
>> Thanx Mark,
>>
>> Here's an updated patch.  I didn't put the truncation logic in a 
>> separate function yet since I'm not sure about freeing the memory of a 
>> returned char* (looking through the code, sometimes pfree is called, 
>> and other times it's not).
>>
>> Cheers,
>> Kevin
> 
> 
> Hi Kevin,
> 
> Please see the new lwmessage_truncate() function I have just committed 
> to liblwgeom in trunk - it should now just be a matter of feeding in the 
> right numbers :)
> 
> Note the function returns a newly-palloced() string, but in the case of 
> throwing an ERROR, I suspect that the query memory context is destroyed 
> automatically and hence will pfree() the string as part of that process.
> 
> 
> HTH,
> 
> Mark.
>