body filters for zero-sized subrequests

[Evan Miller]

Hi Igor,

I have a module that issues subrequests and passes them through a body 
filter. It seems that subrequests with zero size are not passed to the 
body filter. Is this the intended behavior?

Thanks,

Evan



Source:

static ngx_int_t 

ngx_http_zip_body_filter(ngx_http_request_t *r, 

         ngx_chain_t *in) 

{ 

     ngx_http_zip_ctx_t   *ctx; 

     ngx_chain_t          *chain_link; 

     int rc; 

 

     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, 

             "ngx_zip: entering body filter");

     if (r != r->main) { /* subrequest */
...



Excerpts from debug log, main request + non-zero subrequest + zero 
subrequest... "entering body filter" appears twice, not three times:


2007/08/22 01:21:30 [debug] 26369#0: *1 http output filter "/login/zip?"
2007/08/22 01:21:30 [debug] 26369#0: *1 copy filter: "/login/zip?"
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: entering body filter
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: about to parse
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: parsing response buffer 
of length 0
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: parsed 2 file names
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: initiating first of 2 
subrequest(s)
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: subrequest for 
"/static/file.txt?" 08102508
2007/08/22 01:21:30 [debug] 26369#0: *1 http subrequest "/static/file.txt?"
...
2007/08/22 01:21:30 [debug] 26369#0: *1 http output filter 
"/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 copy filter: "/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 read: 9, 08102D70, 68, 0
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: entering body filter
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: adding file header 
"jeebus.html"
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: adding file trailer
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: processed 68/68 bytes 
of file #0
2007/08/22 01:21:30 [debug] 26369#0: *1 http postpone filter 
"/static/file.txt?" 08102DB4
2007/08/22 01:21:30 [debug] 26369#0: *1 http postpone filter out 
"/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 write new buf t:0 f:0 00000000, 
pos 08102DF0, size: 54 file: 0, size: 0
2007/08/22 01:21:30 [debug] 26369#0: *1 write new buf t:1 f:0 08102D70, 
pos 08102D70, size: 68 file: 0, size: 0
2007/08/22 01:21:30 [debug] 26369#0: *1 write new buf t:0 f:0 00000000, 
pos 08102E64, size: 16 file: 0, size: 0
2007/08/22 01:21:30 [debug] 26369#0: *1 http write filter: l:0 f:0 s:138
2007/08/22 01:21:30 [debug] 26369#0: *1 copy filter: 0 "/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 http finalize request: 0, 
"/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 event timer add: 6: 60000:2359976554
2007/08/22 01:21:30 [debug] 26369#0: *1 http parent request: "/login/zip?"
2007/08/22 01:21:30 [debug] 26369#0: *1 http request: "/login/zip?" has 
postponed
2007/08/22 01:21:30 [debug] 26369#0: *1 http fast subrequest: 
"/static/file.txt?" done
2007/08/22 01:21:30 [debug] 26369#0: *1 http subrequest done 
"/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: subrequest for 
"/static/file.txt?" 08102540
...
2007/08/22 01:21:30 [debug] 26369#0: *1 http write filter: l:0 f:0 s:276
2007/08/22 01:21:30 [debug] 26369#0: *1 copy filter: 0 "/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 http finalize request: 0, 
"/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 event timer: 6, old: 2359976554, 
new: 2359976554
2007/08/22 01:21:30 [debug] 26369#0: *1 http parent request: "/login/zip?"
2007/08/22 01:21:30 [debug] 26369#0: *1 http request: "/login/zip?" has 
postponed
2007/08/22 01:21:30 [debug] 26369#0: *1 http fast subrequest: 
"/static/file.txt?" done
2007/08/22 01:21:30 [debug] 26369#0: *1 http subrequest done 
"/static/file.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 ngx_zip: subrequest for 
"/static/zero.txt?" 08102578
2007/08/22 01:21:30 [debug] 26369#0: *1 http subrequest "/static/zero.txt?"
...
2007/08/22 01:21:30 [debug] 26369#0: *1 http finalize request: 0, 
"/static/zero.txt?"
2007/08/22 01:21:30 [debug] 26369#0: *1 event timer: 6, old: 2359976554, 
new: 2359976554
2007/08/22 01:21:30 [debug] 26369#0: *1 http parent request: "/login/zip?"
2007/08/22 01:21:30 [debug] 26369#0: *1 http request: "/login/zip?" has 
postponed
2007/08/22 01:21:30 [debug] 26369#0: *1 http fast subrequest: 
"/static/zero.txt?" done
2007/08/22 01:21:30 [debug] 26369#0: *1 http subrequest done 
"/static/zero.txt?"