nsmcp::BoundedLogScanner method first (protected)

 <instance of nsmcp::BoundedLogScanner> first position ceiling

Defined in /usr/local/ns/tcl/nsmcp/log-01-scanner.tcl

Parameters:

position (required)

ceiling (required)

Testcases:

No testcase defined.

Source code:

set relative [expr {$position-${:bufferFrom}}]
set available [expr {$ceiling-${:bufferFrom}}]
set found -1
# Search the existing bytes directly. A scratch file adds writes and
# descriptor operations without improving the bounded search contract.
set buffer ${:buffer}
foreach key ${:keys} {
    set candidate [string first $key $buffer $relative]
    if {$candidate>=0 && $candidate+[string length $key]<=$available
        && ($found<0 || $candidate<$found)} {
        set found $candidate
    }
}
if {$found>=0} {
    return [expr {${:bufferFrom}+$found}]
}
return -1

XQL Not present:

Generic, PostgreSQL, Oracle