Check validity of residual block before removal in RemoveResidualBlock.
- Breaking change: Problem::Options::enable_fast_parameter_block_removal
is now Problem::Options::enable_fast_removal, as it now controls
the behaviour for both parameter and residual blocks.
- Previously we did not check that the specified residual block to
remove in RemoveResidualBlock actually represented a valid residual
for the problem.
- This meant that Ceres would die unexpectedly if the user passed an
uninitialised residual_block, or more likely attempted to remove a
residual block that had already been removed automatically after
the user removed a parameter block upon on which it was dependent.
- RemoveResidualBlock now verifies the validity of the given
residual_block to remove. Either by checking against a hash set of
all residuals maintained in ProblemImpl iff enable_fast_removal
is enabled. Or by a full scan of the residual blocks if not.
Change-Id: I9ab178e2f68a74135f0a8e20905b16405c77a62b
diff --git a/include/ceres/problem.h b/include/ceres/problem.h
index a7d7815..bed792a 100644
--- a/include/ceres/problem.h
+++ b/include/ceres/problem.h
@@ -124,7 +124,7 @@
: cost_function_ownership(TAKE_OWNERSHIP),
loss_function_ownership(TAKE_OWNERSHIP),
local_parameterization_ownership(TAKE_OWNERSHIP),
- enable_fast_parameter_block_removal(false),
+ enable_fast_removal(false),
disable_all_safety_checks(false) {}
// These flags control whether the Problem object owns the cost
@@ -138,17 +138,21 @@
Ownership loss_function_ownership;
Ownership local_parameterization_ownership;
- // If true, trades memory for a faster RemoveParameterBlock() operation.
+ // If true, trades memory for faster RemoveResidualBlock() and
+ // RemoveParameterBlock() operations.
//
- // RemoveParameterBlock() takes time proportional to the size of the entire
- // Problem. If you only remove parameter blocks from the Problem
- // occassionaly, this may be acceptable. However, if you are modifying the
- // Problem frequently, and have memory to spare, then flip this switch to
+ // By default, RemoveParameterBlock() and RemoveResidualBlock() take time
+ // proportional to the size of the entire problem. If you only ever remove
+ // parameters or residuals from the problem occassionally, this might be
+ // acceptable. However, if you have memory to spare, enable this option to
// make RemoveParameterBlock() take time proportional to the number of
- // residual blocks that depend on it. The increase in memory usage is an
- // additonal hash set per parameter block containing all the residuals that
- // depend on the parameter block.
- bool enable_fast_parameter_block_removal;
+ // residual blocks that depend on it, and RemoveResidualBlock() take (on
+ // average) constant time.
+ //
+ // The increase in memory usage is twofold: an additonal hash set per
+ // parameter block containing all the residuals that depend on the parameter
+ // block; and a hash set in the problem containing all residuals.
+ bool enable_fast_removal;
// By default, Ceres performs a variety of safety checks when constructing
// the problem. There is a small but measurable performance penalty to
@@ -276,7 +280,7 @@
// residual blocks that depend on the parameter are also removed, as
// described above in RemoveResidualBlock().
//
- // If Problem::Options::enable_fast_parameter_block_removal is true, then the
+ // If Problem::Options::enable_fast_removal is true, then the
// removal is fast (almost constant time). Otherwise, removing a parameter
// block will incur a scan of the entire Problem object.
//
@@ -362,7 +366,7 @@
// Get all the residual blocks that depend on the given parameter block.
//
- // If Problem::Options::enable_fast_parameter_block_removal is true, then
+ // If Problem::Options::enable_fast_removal is true, then
// getting the residual blocks is fast and depends only on the number of
// residual blocks. Otherwise, getting the residual blocks for a parameter
// block will incur a scan of the entire Problem object.
