diff options
| -rw-r--r-- | src/cnode/cnode-algorithm.cpp | 100 |
1 files changed, 98 insertions, 2 deletions
diff --git a/src/cnode/cnode-algorithm.cpp b/src/cnode/cnode-algorithm.cpp index 23b5b41..526a218 100644 --- a/src/cnode/cnode-algorithm.cpp +++ b/src/cnode/cnode-algorithm.cpp @@ -212,6 +212,9 @@ _diff_print_indent(const CfgNode *cfg1, const CfgNode *cfg2, int level, } } +/* this is used by "context diff" to print the context in "edit notation" + * like in JUNOS "show | compare". + */ static void _diff_print_context(vector<string>& cur_path) { @@ -222,6 +225,18 @@ _diff_print_context(vector<string>& cur_path) printf("]\n"); } +/* print the comment (if any) at the specified node, including "change + * prefix" (if any). + * + * since a node's comment is printed before the node itself, this will + * print the "context" first if doing context diff. + * + * cur_path: the current context (for context diff). + * context_diff: whether we're doing context diff. + * + * return whether anything is printed. this is only used for context diff + * (caller does different things according to return value). + */ static bool _diff_print_comment(const CfgNode *cfg1, const CfgNode *cfg2, int level, vector<string>& cur_path, bool context_diff) @@ -260,9 +275,15 @@ _diff_print_comment(const CfgNode *cfg1, const CfgNode *cfg2, int level, // no comment return false; } + /* print comment if + * * not doing context diff + * OR + * * doing context diff and there is actually a difference + */ if (!context_diff || (pfx_diff != PFX_DIFF_NONE.c_str() && pfx_diff != PFX_DIFF_NULL.c_str())) { if (context_diff) { + // print context first _diff_print_context(cur_path); } _diff_print_indent(cfg1, cfg2, level, pfx_diff); @@ -299,6 +320,11 @@ _diff_check_and_show_leaf(const CfgNode *cfg1, const CfgNode *cfg2, int level, bool cprint = _diff_print_comment(cfg1, cfg2, level, cur_path, context_diff); if (cprint) { + /* when doing context diff, normally we only show the node if there is a + * difference. however, if something was printed for comment, the node + * should be printed even if there is no difference. so set context_diff + * to false to force the node to be displayed. + */ context_diff = false; } if (cfg->isMulti()) { @@ -306,9 +332,13 @@ _diff_check_and_show_leaf(const CfgNode *cfg1, const CfgNode *cfg2, int level, if (force_pfx_diff) { // simple case: just use the same diff prefix for all values if (!cprint && context_diff) { + /* if nothing was printed for comment and we're doing context diff, + * then context hasn't been displayed yet. so print it first. + */ _diff_print_context(cur_path); } if (!context_diff || force_pfx_diff != PFX_DIFF_NULL.c_str()) { + // not context diff OR there is a difference => print the node const vector<string>& vvec = cfg->getValues(); for (size_t i = 0; i < vvec.size(); i++) { _diff_print_indent(cfg1, cfg2, level, force_pfx_diff); @@ -323,11 +353,19 @@ _diff_check_and_show_leaf(const CfgNode *cfg1, const CfgNode *cfg2, int level, vector<const char *> pfxs; bool changed = _cmp_multi_values(cfg1, cfg2, values, pfxs); if (!context_diff || changed) { + // not context diff OR there is a difference => print the node for (size_t i = 0; i < values.size(); i++) { if (context_diff && pfxs[i] == PFX_DIFF_NONE.c_str()) { + // not printing unchanged values if doing context diff continue; } if (!cprint && context_diff) { + /* if nothing was printed for comment and we're doing context + * diff, then context hasn't been displayed yet. so print it + * first. note that we only want to see the context once, so + * set cprint to true so that later iterations won't print it + * again. + */ _diff_print_context(cur_path); cprint = true; } @@ -354,7 +392,11 @@ _diff_check_and_show_leaf(const CfgNode *cfg1, const CfgNode *cfg2, int level, bool changed = (force_pfx_diff != PFX_DIFF_NONE.c_str() && force_pfx_diff != PFX_DIFF_NULL.c_str()); if (!context_diff || changed) { + // not context diff OR there is a difference => print the node if (!cprint && context_diff) { + /* if nothing was printed for comment and we're doing context diff, + * then context hasn't been displayed yet. so print it first. + */ _diff_print_context(cur_path); } _diff_print_indent(cfg1, cfg2, level, force_pfx_diff); @@ -401,10 +443,39 @@ _diff_show_other(const CfgNode *cfg1, const CfgNode *cfg2, int level, if (print_this) { bool cprint = _diff_print_comment(cfg1, cfg2, level, cur_path, orig_cdiff); if (orig_cdiff && pfx_diff != PFX_DIFF_NONE.c_str()) { + /* note: + * orig_cdiff is the original value of context_diff. + * pfx_diff is set above. + * so the condition here means + * (1) when this function is called, we are doing a context diff + * AND + * (2) pfx_diff is either PFX_DIFF_ADD or PFX_DIFF_DEL, i.e., one + * and only one of cfg1 and cfg2 is NULL. + * + * note that pfx_diff cannot be PFX_DIFF_NULL since + * (cfg1 == cfg2) cannot be true if context_diff is true (see + * caller's logic). + * + * since one and only one of cfg1 and cfg2 is NULL, it means that the + * whole subtree rooted at the current node is "added" or "deleted". + * therefore, set context_diff to false for the recursion into this + * subtree so that it will be displayed normally. + */ context_diff = false; } if (cprint || !orig_cdiff || pfx_diff != PFX_DIFF_NONE.c_str()) { + /* print this node if + * (1) something was printed for comment, in which case the node + * should be printed regardless of whether there is a difference. + * OR + * (2) not doing context diff. + * OR + * (3) there is a difference. + */ if (!cprint && orig_cdiff) { + /* if nothing was printed for comment and we're doing context diff, + * then context hasn't been displayed yet. so print it first. + */ _diff_print_context(cur_path); } _diff_print_indent(cfg1, cfg2, level, pfx_diff); @@ -415,7 +486,22 @@ _diff_show_other(const CfgNode *cfg1, const CfgNode *cfg2, int level, // at intermediate node printf("%s", name.c_str()); } - if (cprint && pfx_diff == PFX_DIFF_NONE.c_str()) { + if (cprint && orig_cdiff && pfx_diff == PFX_DIFF_NONE.c_str()) { + /* the condition means: + * (1) something was printed for comment. + * AND + * (2) doing context diff. + * AND + * (3) there is no difference for the node itself. + * + * this means we are only printing the node for the comment. so just + * print "{ ... }" to represent the subtree like JUNOS + * "show | compare". any difference in the subtree will be handled + * later by the recursion into it. + * + * in this case also set is_leaf_typeless to true to prevent a + * dangling "}\n" from being printed at the end of this function. + */ printf(" { ... }\n"); is_leaf_typeless = true; } else { @@ -443,6 +529,10 @@ _diff_show_other(const CfgNode *cfg1, const CfgNode *cfg2, int level, cur_path.pop_back(); } if (!orig_cdiff || pfx_diff != PFX_DIFF_NONE.c_str()) { + /* not context diff OR there is a difference => print closing '}' + * if necessary. also note the exception above where is_leaf_typeless + * is set to true to prevent this. + */ if (!is_leaf_typeless) { _diff_print_indent(cfg1, cfg2, level, pfx_diff); printf("}\n"); @@ -484,9 +574,15 @@ _show_diff(const CfgNode *cfg1, const CfgNode *cfg2, int level, if (context_diff) { if (cfg1 == cfg2) { - // nothing to do for context diff + /* nothing to do for context diff so stop the recursion. this also + * means that during the recursion cfg1 and cfg2 must be different + * if doing context diff. + */ return; } + /* when doing context diff, the display indentation level always starts + * at 0. + */ level = 0; } |