From ff0fd91ed23ae9d851bf27c4df3ec77f7028699b Mon Sep 17 00:00:00 2001 From: pennae Date: Sat, 5 Mar 2022 14:20:25 +0100 Subject: remove Symbol::empty the only use of this function is to determine whether a lambda has a non-set formal, but this use is arguably better served by Symbol::set and using a non-Symbol instead of an empty symbol in the parser when no such formal is present. --- src/libexpr/value-to-xml.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libexpr/value-to-xml.cc') diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc index afeaf5694..7f8edcba6 100644 --- a/src/libexpr/value-to-xml.cc +++ b/src/libexpr/value-to-xml.cc @@ -139,7 +139,7 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, if (v.lambda.fun->hasFormals()) { XMLAttrs attrs; - if (!v.lambda.fun->arg.empty()) attrs["name"] = v.lambda.fun->arg; + if (v.lambda.fun->arg.set()) attrs["name"] = v.lambda.fun->arg; if (v.lambda.fun->formals->ellipsis) attrs["ellipsis"] = "1"; XMLOpenElement _(doc, "attrspat", attrs); for (auto & i : v.lambda.fun->formals->lexicographicOrder()) -- cgit v1.2.3 From 6526d1676ba5a645f65d751e7529ccd273579017 Mon Sep 17 00:00:00 2001 From: pennae Date: Fri, 4 Mar 2022 19:31:59 +0100 Subject: replace most Pos objects/ptrs with indexes into a position table Pos objects are somewhat wasteful as they duplicate the origin file name and input type for each object. on files that produce more than one Pos when parsed this a sizeable waste of memory (one pointer per Pos). the same goes for ptr on 64 bit machines: parsing enough source to require 8 bytes to locate a position would need at least 8GB of input and 64GB of expression memory. it's not likely that we'll hit that any time soon, so we can use a uint32_t index to locate positions instead. --- src/libexpr/value-to-xml.cc | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'src/libexpr/value-to-xml.cc') diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc index 7f8edcba6..d1e0c4778 100644 --- a/src/libexpr/value-to-xml.cc +++ b/src/libexpr/value-to-xml.cc @@ -19,7 +19,7 @@ static XMLAttrs singletonAttrs(const std::string & name, const std::string & val static void printValueAsXML(EvalState & state, bool strict, bool location, Value & v, XMLWriter & doc, PathSet & context, PathSet & drvsSeen, - const Pos & pos); + const PosIdx pos); static void posToXML(XMLAttrs & xmlAttrs, const Pos & pos) @@ -43,18 +43,18 @@ static void showAttrs(EvalState & state, bool strict, bool location, XMLAttrs xmlAttrs; xmlAttrs["name"] = i; - if (location && a.pos != ptr(&noPos)) posToXML(xmlAttrs, *a.pos); + if (location && a.pos) posToXML(xmlAttrs, state.positions[a.pos]); XMLOpenElement _(doc, "attr", xmlAttrs); printValueAsXML(state, strict, location, - *a.value, doc, context, drvsSeen, *a.pos); + *a.value, doc, context, drvsSeen, a.pos); } } static void printValueAsXML(EvalState & state, bool strict, bool location, Value & v, XMLWriter & doc, PathSet & context, PathSet & drvsSeen, - const Pos & pos) + const PosIdx pos) { checkInterrupt(); @@ -93,14 +93,14 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, Path drvPath; a = v.attrs->find(state.sDrvPath); if (a != v.attrs->end()) { - if (strict) state.forceValue(*a->value, *a->pos); + if (strict) state.forceValue(*a->value, a->pos); if (a->value->type() == nString) xmlAttrs["drvPath"] = drvPath = a->value->string.s; } a = v.attrs->find(state.sOutPath); if (a != v.attrs->end()) { - if (strict) state.forceValue(*a->value, *a->pos); + if (strict) state.forceValue(*a->value, a->pos); if (a->value->type() == nString) xmlAttrs["outPath"] = a->value->string.s; } @@ -134,7 +134,7 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, break; } XMLAttrs xmlAttrs; - if (location) posToXML(xmlAttrs, v.lambda.fun->pos); + if (location) posToXML(xmlAttrs, state.positions[v.lambda.fun->pos]); XMLOpenElement _(doc, "function", xmlAttrs); if (v.lambda.fun->hasFormals()) { @@ -166,14 +166,14 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, void ExternalValueBase::printValueAsXML(EvalState & state, bool strict, bool location, XMLWriter & doc, PathSet & context, PathSet & drvsSeen, - const Pos & pos) const + const PosIdx pos) const { doc.writeEmptyElement("unevaluated"); } void printValueAsXML(EvalState & state, bool strict, bool location, - Value & v, std::ostream & out, PathSet & context, const Pos & pos) + Value & v, std::ostream & out, PathSet & context, const PosIdx pos) { XMLWriter doc(true, out); XMLOpenElement root(doc, "expr"); -- cgit v1.2.3 From 8775be33931ec3b1cad97035ff3d5370a97178a1 Mon Sep 17 00:00:00 2001 From: pennae Date: Sat, 5 Mar 2022 14:40:24 +0100 Subject: store Symbols in a table as well, like positions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit this slightly increases the amount of memory used for any given symbol, but this increase is more than made up for if the symbol is referenced more than once in the EvalState that holds it. on average every symbol should be referenced at least twice (once to introduce a binding, once to use it), so we expect no increase in memory on average. symbol tables are limited to 2³² entries like position tables, and similar arguments apply to why overflow is not likely: 2³² symbols would require as many string instances (at 24 bytes each) and map entries (at 24 bytes or more each, assuming that the map holds on average at most one item per bucket as the docs say). a full symbol table would require at least 192GB of memory just for symbols, which is well out of reach. (an ofborg eval of nixpks today creates less than a million symbols!) --- src/libexpr/value-to-xml.cc | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'src/libexpr/value-to-xml.cc') diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc index d1e0c4778..7c3bf9492 100644 --- a/src/libexpr/value-to-xml.cc +++ b/src/libexpr/value-to-xml.cc @@ -22,7 +22,7 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, const PosIdx pos); -static void posToXML(XMLAttrs & xmlAttrs, const Pos & pos) +static void posToXML(EvalState & state, XMLAttrs & xmlAttrs, const Pos & pos) { xmlAttrs["path"] = pos.file; xmlAttrs["line"] = (format("%1%") % pos.line).str(); @@ -36,14 +36,14 @@ static void showAttrs(EvalState & state, bool strict, bool location, StringSet names; for (auto & i : attrs) - names.insert(i.name); + names.emplace(state.symbols[i.name]); for (auto & i : names) { Attr & a(*attrs.find(state.symbols.create(i))); XMLAttrs xmlAttrs; xmlAttrs["name"] = i; - if (location && a.pos) posToXML(xmlAttrs, state.positions[a.pos]); + if (location && a.pos) posToXML(state, xmlAttrs, state.positions[a.pos]); XMLOpenElement _(doc, "attr", xmlAttrs); printValueAsXML(state, strict, location, @@ -134,18 +134,18 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, break; } XMLAttrs xmlAttrs; - if (location) posToXML(xmlAttrs, state.positions[v.lambda.fun->pos]); + if (location) posToXML(state, xmlAttrs, state.positions[v.lambda.fun->pos]); XMLOpenElement _(doc, "function", xmlAttrs); if (v.lambda.fun->hasFormals()) { XMLAttrs attrs; - if (v.lambda.fun->arg.set()) attrs["name"] = v.lambda.fun->arg; + if (v.lambda.fun->arg) attrs["name"] = state.symbols[v.lambda.fun->arg]; if (v.lambda.fun->formals->ellipsis) attrs["ellipsis"] = "1"; XMLOpenElement _(doc, "attrspat", attrs); - for (auto & i : v.lambda.fun->formals->lexicographicOrder()) - doc.writeEmptyElement("attr", singletonAttrs("name", i.name)); + for (auto & i : v.lambda.fun->formals->lexicographicOrder(state.symbols)) + doc.writeEmptyElement("attr", singletonAttrs("name", state.symbols[i.name])); } else - doc.writeEmptyElement("varpat", singletonAttrs("name", v.lambda.fun->arg)); + doc.writeEmptyElement("varpat", singletonAttrs("name", state.symbols[v.lambda.fun->arg])); break; } -- cgit v1.2.3