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/primops/fetchTree.cc | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) (limited to 'src/libexpr/primops/fetchTree.cc') diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc index 42c98e312..cdcae97b6 100644 --- a/src/libexpr/primops/fetchTree.cc +++ b/src/libexpr/primops/fetchTree.cc @@ -90,7 +90,7 @@ struct FetchTreeParams { static void fetchTree( EvalState & state, - const Pos & pos, + const PosIdx pos, Value * * args, Value & v, std::optional type, @@ -110,22 +110,22 @@ static void fetchTree( if (type) throw Error({ .msg = hintfmt("unexpected attribute 'type'"), - .errPos = pos + .errPos = state.positions[pos] }); - type = state.forceStringNoCtx(*aType->value, *aType->pos); + type = state.forceStringNoCtx(*aType->value, aType->pos); } else if (!type) throw Error({ .msg = hintfmt("attribute 'type' is missing in call to 'fetchTree'"), - .errPos = pos + .errPos = state.positions[pos] }); attrs.emplace("type", type.value()); for (auto & attr : *args[0]->attrs) { if (attr.name == state.sType) continue; - state.forceValue(*attr.value, *attr.pos); + state.forceValue(*attr.value, attr.pos); if (attr.value->type() == nPath || attr.value->type() == nString) { - auto s = state.coerceToString(*attr.pos, *attr.value, context, false, false).toOwned(); + auto s = state.coerceToString(attr.pos, *attr.value, context, false, false).toOwned(); attrs.emplace(attr.name, attr.name == "url" ? type == "git" @@ -146,7 +146,7 @@ static void fetchTree( if (auto nameIter = attrs.find("name"); nameIter != attrs.end()) throw Error({ .msg = hintfmt("attribute 'name' isn't supported in call to 'fetchTree'"), - .errPos = pos + .errPos = state.positions[pos] }); input = fetchers::Input::fromAttrs(std::move(attrs)); @@ -167,7 +167,7 @@ static void fetchTree( input = lookupInRegistries(state.store, input).first; if (evalSettings.pureEval && !input.isLocked()) - throw Error("in pure evaluation mode, 'fetchTree' requires a locked input, at %s", pos); + throw Error("in pure evaluation mode, 'fetchTree' requires a locked input, at %s", state.positions[pos]); auto [tree, input2] = input.fetch(state.store); @@ -176,7 +176,7 @@ static void fetchTree( emitTreeAttrs(state, tree, input2, v, params.emptyRevFallback, false); } -static void prim_fetchTree(EvalState & state, const Pos & pos, Value * * args, Value & v) +static void prim_fetchTree(EvalState & state, const PosIdx pos, Value * * args, Value & v) { settings.requireExperimentalFeature(Xp::Flakes); fetchTree(state, pos, args, v, std::nullopt, FetchTreeParams { .allowNameArgument = false }); @@ -185,7 +185,7 @@ static void prim_fetchTree(EvalState & state, const Pos & pos, Value * * args, V // FIXME: document static RegisterPrimOp primop_fetchTree("fetchTree", 1, prim_fetchTree); -static void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v, +static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v, const std::string & who, bool unpack, std::string name) { std::optional url; @@ -200,22 +200,22 @@ static void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v, for (auto & attr : *args[0]->attrs) { std::string n(attr.name); if (n == "url") - url = state.forceStringNoCtx(*attr.value, *attr.pos); + url = state.forceStringNoCtx(*attr.value, attr.pos); else if (n == "sha256") - expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256); + expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos), htSHA256); else if (n == "name") - name = state.forceStringNoCtx(*attr.value, *attr.pos); + name = state.forceStringNoCtx(*attr.value, attr.pos); else throw EvalError({ .msg = hintfmt("unsupported argument '%s' to '%s'", attr.name, who), - .errPos = *attr.pos + .errPos = state.positions[attr.pos] }); } if (!url) throw EvalError({ .msg = hintfmt("'url' argument required"), - .errPos = pos + .errPos = state.positions[pos] }); } else url = state.forceStringNoCtx(*args[0], pos); @@ -262,7 +262,7 @@ static void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v, state.allowAndSetStorePathString(storePath, v); } -static void prim_fetchurl(EvalState & state, const Pos & pos, Value * * args, Value & v) +static void prim_fetchurl(EvalState & state, const PosIdx pos, Value * * args, Value & v) { fetch(state, pos, args, v, "fetchurl", false, ""); } @@ -278,7 +278,7 @@ static RegisterPrimOp primop_fetchurl({ .fun = prim_fetchurl, }); -static void prim_fetchTarball(EvalState & state, const Pos & pos, Value * * args, Value & v) +static void prim_fetchTarball(EvalState & state, const PosIdx pos, Value * * args, Value & v) { fetch(state, pos, args, v, "fetchTarball", true, "source"); } @@ -329,7 +329,7 @@ static RegisterPrimOp primop_fetchTarball({ .fun = prim_fetchTarball, }); -static void prim_fetchGit(EvalState & state, const Pos & pos, Value * * args, Value & v) +static void prim_fetchGit(EvalState & state, const PosIdx pos, Value * * args, Value & v) { fetchTree(state, pos, args, v, "git", FetchTreeParams { .emptyRevFallback = true, .allowNameArgument = true }); } -- 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/primops/fetchTree.cc | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'src/libexpr/primops/fetchTree.cc') diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc index cdcae97b6..d7c3c9918 100644 --- a/src/libexpr/primops/fetchTree.cc +++ b/src/libexpr/primops/fetchTree.cc @@ -126,20 +126,20 @@ static void fetchTree( state.forceValue(*attr.value, attr.pos); if (attr.value->type() == nPath || attr.value->type() == nString) { auto s = state.coerceToString(attr.pos, *attr.value, context, false, false).toOwned(); - attrs.emplace(attr.name, - attr.name == "url" + attrs.emplace(state.symbols[attr.name], + state.symbols[attr.name] == "url" ? type == "git" ? fixURIForGit(s, state) : fixURI(s, state) : s); } else if (attr.value->type() == nBool) - attrs.emplace(attr.name, Explicit{attr.value->boolean}); + attrs.emplace(state.symbols[attr.name], Explicit{attr.value->boolean}); else if (attr.value->type() == nInt) - attrs.emplace(attr.name, uint64_t(attr.value->integer)); + attrs.emplace(state.symbols[attr.name], uint64_t(attr.value->integer)); else throw TypeError("fetchTree argument '%s' is %s while a string, Boolean or integer is expected", - attr.name, showType(*attr.value)); + state.symbols[attr.name], showType(*attr.value)); } if (!params.allowNameArgument) @@ -198,7 +198,7 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v state.forceAttrs(*args[0], pos); for (auto & attr : *args[0]->attrs) { - std::string n(attr.name); + std::string_view n(state.symbols[attr.name]); if (n == "url") url = state.forceStringNoCtx(*attr.value, attr.pos); else if (n == "sha256") @@ -207,7 +207,7 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v name = state.forceStringNoCtx(*attr.value, attr.pos); else throw EvalError({ - .msg = hintfmt("unsupported argument '%s' to '%s'", attr.name, who), + .msg = hintfmt("unsupported argument '%s' to '%s'", n, who), .errPos = state.positions[attr.pos] }); } -- cgit v1.2.3