Yes, thanks for looking at it, Eric. It is correct after I flatten it: output: _ASCII_String0_!__ASCII_String4_!ASCII_String1_!_ASCII_String2_!_ASCII_String3_! but not when reading the bucket with apr_bucket_read(Index, &TestBuffer, &Length, APR_BLOCK_READ): Marker: 1 CurrBucket: _ASCII_String1_! Length: 1 Bucket1 is not just "_". It looks like apr_bucket_read returns the memory location of the original string and does no manipulation like null termination when splitting. So I guess that I cannot simply call printf, and that I must either use putchar with a loop or snprintf, strncpy, memcpy, etc. One of the reasons for this exercise is to understand the difference between transient and immortal buckets. I don't get memory errors when running valgrind and mis-matching the transient, immortal, and even pool buckets with the memory they were used to create them. I don't want to embark on using this library without a good understanding of what is going on. I have a better idea now, but still many questions remain. I looked at http://www.apachetutor.org/dev/brigades, but that doesn't explain much. The tests in the source code archive helped a bit. Is there any good reading about this on the interwebs? ;) Simon On 01/02/2018 12:51 AM, Eric Covener wrote: >> I see such code as the example you gave in various places. However, this >> bit of code (attached) shows me that I cannot simply printf the data. >> Again, I am probably doing something wrong. >> > > The output looks right to me but maybe I am misunderstanding the > intent of the example. > > output: _ASCII_String0_!__ASCII_String4_!ASCII_String1_!_ASCII_String2_!_ASCII_String3_! > ^ extra underscore is b1 > ^ b4 inserted heree > ^ > b1_1 and the missing underscore from the split and > > > You start with b0,b1,b2,b3 and iterate over the brigade. > > While looking at b1, you split it at index 1 into two buckets. b1 is > now just "_" and b1_1 is the rest. > > b0, b1, b1_1, b2, b3 > > You then insert b4 after b1: > > b0, b1, b1_1, b2, b3 > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx > For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx >
#include <stdlib.h>
#include <linux/limits.h>
#include <apr-1.0/apr_buckets.h>
int main(int ArgCount, char * Arg[])
{
apr_initialize();
atexit(apr_terminate);
apr_pool_t * Pool;
apr_pool_create(&Pool, NULL);
apr_bucket_alloc_t * BucketAlloc = apr_bucket_alloc_create(Pool);
apr_bucket_brigade * Brigade = apr_brigade_create(Pool, BucketAlloc);
char * String0 = calloc(strlen("_ASCII_String0_!") + 1, 1);
strcpy(String0, "_ASCII_String0_!");
printf("Address of String0 = %p\n", (void *)(String0));
apr_bucket * Bucket0 = apr_bucket_immortal_create(String0, strlen(String0), BucketAlloc);
APR_BRIGADE_INSERT_TAIL(Brigade, Bucket0);
char * String1 = calloc(strlen("_ASCII_String1_!") + 1, 1);
strcpy(String1, "_ASCII_String1_!");
printf("Address of String1 = %p\n", (void *)(String1));
apr_bucket * Bucket1 = apr_bucket_immortal_create(String1, strlen(String1), BucketAlloc);
APR_BRIGADE_INSERT_TAIL(Brigade, Bucket1);
char * String2 = "_ASCII_String2_!";
printf("Address of String2 = %p\n", (void *)(String2));
apr_bucket * Bucket2 = apr_bucket_transient_create(String2, strlen(String2), BucketAlloc);
APR_BRIGADE_INSERT_TAIL(Brigade, Bucket2);
char * String3 = "_ASCII_String3_!";
printf("Address of String3 = %p\n", (void *)(String3));
apr_bucket * Bucket3 = apr_bucket_transient_create(String3, strlen(String3), BucketAlloc);
APR_BRIGADE_INSERT_TAIL(Brigade, Bucket3);
char * String4 = apr_pcalloc(Pool, strlen("_ASCII_String4_!") + 1);
strcpy(String4, "_ASCII_String4_!");
printf("Address of String4 = %p\n", (void *)(String4));
apr_bucket * Bucket4 = apr_bucket_pool_create(String4, strlen(String4), Pool, BucketAlloc);
apr_bucket * Index;
const char * TestBuffer = NULL;
int Marker = 0;
int PutIndex = 0;
size_t Length = 0;
for (Index = APR_BRIGADE_FIRST(Brigade); Index != APR_BRIGADE_SENTINEL(Brigade); Index = APR_BUCKET_NEXT(Index))
{
printf("Marker: %d\n", Marker);
if (Marker == 1)
{
apr_bucket_split(Index, 1);
printf("Address of String1 + 1 = %p\n", (void *)(String1 + 1));
APR_BUCKET_INSERT_AFTER(Index, Bucket4);
}
TestBuffer = NULL;
Length = 0;
if (apr_bucket_read(Index, &TestBuffer, &Length, APR_BLOCK_READ) == APR_SUCCESS)
{
printf("CurrBucket: ");
PutIndex = 0;
while (PutIndex < Length) putchar(*(TestBuffer + PutIndex++));
printf("\n");
printf("Address of TestBuffer = %p\n", (void *)(TestBuffer));
printf("Length: %zu\n", Length);
}
Marker++;
}
char * Output0 = NULL;
apr_size_t Output0Length = 0;
apr_brigade_pflatten(Brigade, &Output0, &Output0Length, Pool);
printf("Output0: %s\n", Output0);
printf("Output0 Length: %zu\n", Output0Length);
printf("Address of Output0 = %p\n", (void *)(Output0));
apr_off_t BrigadeLength;
apr_brigade_length(Brigade, 1, &BrigadeLength);
printf("BrigadeLength Length: %zu\n", BrigadeLength);
char * Output1 = calloc(BrigadeLength + 1, 1);
apr_size_t Output1Length = BrigadeLength;
apr_brigade_flatten(Brigade, Output1, &Output1Length);
printf("Output1: %s\n", Output1);
printf("Output1 Length: %zu\n", Output1Length);
printf("Address of Output1 = %p\n", (void *)(Output1));
free(String0);
free(String1);
free(Output1);
apr_pool_destroy(Pool);
}
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