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Code Issues 349 Code Review (Gerrit) Projects 3 Releases Wiki Activity

* Refactorings.

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This commit is contained in:
Eelco Dolstra 2003-07-20 19:29:38 +00:00
parent ab350eafd2
commit 6f1a0f948d
14 changed files with 635 additions and 605 deletions
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3
src/Makefile.am
View file

@ -20,7 +20,8 @@ test_LDADD = libshared.a libnix.a -ldb_cxx-4 -lATerm
noinst_LIBRARIES = libnix.a libshared.a
libnix_a_SOURCES = util.cc hash.cc archive.cc md5.c \
fstate.cc store.cc globals.cc db.cc references.cc
store.cc fstate.cc normalise.cc exec.cc \
globals.cc db.cc references.cc
libshared_a_SOURCES = shared.cc

123
src/exec.cc Normal file
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@ -0,0 +1,123 @@
#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include "exec.hh"
#include "util.hh"
#include "globals.hh"
class AutoDelete
{
string path;
bool del;
public:
AutoDelete(const string & p) : path(p)
{
del = true;
}
~AutoDelete()
{
if (del) deletePath(path);
}
void cancel()
{
del = false;
}
};
/* Run a program. */
void runProgram(const string & program, Environment env)
{
/* Create a log file. */
string logFileName = nixLogDir + "/run.log";
/* !!! auto-pclose on exit */
FILE * logFile = popen(("tee -a " + logFileName + " >&2").c_str(), "w"); /* !!! escaping */
if (!logFile)
throw SysError(format("creating log file `%1%'") % logFileName);
/* Create a temporary directory where the build will take
place. */
static int counter = 0;
string tmpDir = (format("/tmp/nix-%1%-%2%") % getpid() % counter++).str();
if (mkdir(tmpDir.c_str(), 0777) == -1)
throw SysError(format("creating directory `%1%'") % tmpDir);
AutoDelete delTmpDir(tmpDir);
/* Fork a child to build the package. */
pid_t pid;
switch (pid = fork()) {
case -1:
throw SysError("unable to fork");
case 0:
try { /* child */
if (chdir(tmpDir.c_str()) == -1)
throw SysError(format("changing into to `%1%'") % tmpDir);
/* Fill in the environment. We don't bother freeing
the strings, since we'll exec or die soon
anyway. */
const char * env2[env.size() + 1];
int i = 0;
for (Environment::iterator it = env.begin();
it != env.end(); it++, i++)
env2[i] = (new string(it->first + "=" + it->second))->c_str();
env2[i] = 0;
/* Dup the log handle into stderr. */
if (dup2(fileno(logFile), STDERR_FILENO) == -1)
throw SysError("cannot pipe standard error into log file");
/* Dup stderr to stdin. */
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
throw SysError("cannot dup stderr into stdout");
/* Make the program executable. !!! hack. */
if (chmod(program.c_str(), 0755))
throw SysError("cannot make program executable");
/* Execute the program. This should not return. */
execle(program.c_str(), baseNameOf(program).c_str(), 0, env2);
throw SysError(format("unable to execute %1%") % program);
} catch (exception & e) {
cerr << format("build error: %1%\n") % e.what();
}
_exit(1);
}
/* parent */
/* Close the logging pipe. Note that this should not cause
the logger to exit until builder exits (because the latter
has an open file handle to the former). */
pclose(logFile);
/* Wait for the child to finish. */
int status;
if (waitpid(pid, &status, 0) != pid)
throw Error("unable to wait for child");
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
delTmpDir.cancel();
throw Error("unable to build package");
}
}

18
src/exec.hh Normal file
View file

@ -0,0 +1,18 @@
#ifndef __EXEC_H
#define __EXEC_H
#include <string>
#include <map>
using namespace std;
/* A Unix environment is a mapping from strings to strings. */
typedef map<string, string> Environment;
/* Run a program. */
void runProgram(const string & program, Environment env);
#endif /* !__EXEC_H */

74
src/fix.cc
View file

@ -2,8 +2,7 @@
#include <iostream>
#include "globals.hh"
#include "fstate.hh"
#include "store.hh"
#include "normalise.hh"
#include "shared.hh"
@ -111,12 +110,11 @@ static Expr evalExpr(Expr e)
ATmatch(e, "FSId(<str>)", &s1))
return e;
if (ATgetType(e) == AT_APPL &&
((string) ATgetName(ATgetAFun(e)) == "Slice" ||
(string) ATgetName(ATgetAFun(e)) == "Derive"))
{
try {
parseFState(e);
return ATmake("FSId(<str>)",
((string) writeTerm(e, "", 0)).c_str());
((string) writeTerm(e, "")).c_str());
} catch (...) { /* !!! catch parse errors only */
}
/* Application. */
@ -139,10 +137,17 @@ static Expr evalExpr(Expr e)
string dstPath;
FSId id;
addToStore(srcPath, dstPath, id, true);
FState fs = ATmake("Slice([<str>], [(<str>, <str>, [])])",
((string) id).c_str(), dstPath.c_str(), ((string) id).c_str());
SliceElem elem;
elem.path = dstPath;
elem.id = id;
FState fs;
fs.type = FState::fsSlice;
fs.slice.roots.push_back(id);
fs.slice.elems.push_back(elem);
return ATmake("FSId(<str>)",
((string) writeTerm(fs, "", 0)).c_str());
((string) writeTerm(unparseFState(fs), "")).c_str());
}
/* Packages are transformed into Derive fstate expressions. */
@ -160,8 +165,10 @@ static Expr evalExpr(Expr e)
}
/* Gather information for building the Derive expression. */
ATermList ins = ATempty, env = ATempty;
string builder, name;
FState fs;
fs.type = FState::fsDerive;
fs.derive.platform = SYSTEM;
string name;
bnds = ATempty;
for (map<string, ATerm>::iterator it = bndMap.begin();
@ -169,21 +176,19 @@ static Expr evalExpr(Expr e)
{
string key = it->first;
ATerm value = it->second;
char * id;
if (ATmatch(value, "FSId(<str>)", &id)) {
Strings paths = fstatePaths(parseHash(id), false);
if (ATmatch(value, "FSId(<str>)", &s1)) {
FSId id = parseHash(s1);
Strings paths = fstatePaths(id, false);
if (paths.size() != 1) abort();
string path = *(paths.begin());
ins = ATinsert(ins, ATmake("<str>", id));
env = ATinsert(env, ATmake("(<str>, <str>)",
key.c_str(), path.c_str()));
if (key == "build") builder = path;
fs.derive.inputs.push_back(id);
fs.derive.env.push_back(StringPair(key, path));
if (key == "build") fs.derive.builder = path;
}
else if (ATmatch(value, "<str>", &s1)) {
if (key == "name") name = s1;
env = ATinsert(env,
ATmake("(<str>, <str>)", key.c_str(), s1));
fs.derive.env.push_back(StringPair(key, s1));
}
else throw badTerm("invalid package argument", value);
@ -191,31 +196,24 @@ static Expr evalExpr(Expr e)
ATmake("(<str>, <term>)", key.c_str(), value));
}
/* Hash the normal form to produce a unique but deterministic
path name for this package. */
ATerm nf = ATmake("Package(<term>)", ATreverse(bnds));
FSId outId = hashTerm(nf);
if (builder == "")
throw badTerm("no builder specified", nf);
if (fs.derive.builder == "")
throw badTerm("no builder specified", e);
if (name == "")
throw badTerm("no package name specified", nf);
throw badTerm("no package name specified", e);
/* Hash the fstate-expression with no outputs to produce a
unique but deterministic path name for this package. */
Hash outId = hashTerm(unparseFState(fs));
string outPath =
canonPath(nixStore + "/" + ((string) outId).c_str() + "-" + name);
env = ATinsert(env, ATmake("(<str>, <str>)", "out", outPath.c_str()));
/* Construct the result. */
FState fs =
ATmake("Derive([(<str>, <str>)], <term>, <str>, <str>, <term>)",
outPath.c_str(), ((string) outId).c_str(),
ins, builder.c_str(), SYSTEM, env);
fs.derive.env.push_back(StringPair("out", outPath));
fs.derive.outputs.push_back(DeriveOutput(outPath, outId));
debug(format("%1%: %2%") % (string) outId % name);
/* Write the resulting term into the Nix store directory. */
return ATmake("FSId(<str>)",
((string) writeTerm(fs, "-d-" + name, 0)).c_str());
((string) writeTerm(unparseFState(fs), "-d-" + name)).c_str());
}
/* BaseName primitive function. */

585
src/fstate.cc
View file

@ -1,141 +1,6 @@
#include <map>
#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include "fstate.hh"
#include "globals.hh"
#include "store.hh"
#include "db.hh"
#include "references.hh"
/* A Unix environment is a mapping from strings to strings. */
typedef map<string, string> Environment;
class AutoDelete
{
string path;
bool del;
public:
AutoDelete(const string & p) : path(p)
{
del = true;
}
~AutoDelete()
{
if (del) deletePath(path);
}
void cancel()
{
del = false;
}
};
/* Run a program. */
static void runProgram(const string & program, Environment env)
{
/* Create a log file. */
string logFileName = nixLogDir + "/run.log";
/* !!! auto-pclose on exit */
FILE * logFile = popen(("tee -a " + logFileName + " >&2").c_str(), "w"); /* !!! escaping */
if (!logFile)
throw SysError(format("creating log file `%1%'") % logFileName);
/* Create a temporary directory where the build will take
place. */
static int counter = 0;
string tmpDir = (format("/tmp/nix-%1%-%2%") % getpid() % counter++).str();
if (mkdir(tmpDir.c_str(), 0777) == -1)
throw SysError(format("creating directory `%1%'") % tmpDir);
AutoDelete delTmpDir(tmpDir);
/* Fork a child to build the package. */
pid_t pid;
switch (pid = fork()) {
case -1:
throw SysError("unable to fork");
case 0:
try { /* child */
if (chdir(tmpDir.c_str()) == -1)
throw SysError(format("changing into to `%1%'") % tmpDir);
/* Fill in the environment. We don't bother freeing
the strings, since we'll exec or die soon
anyway. */
const char * env2[env.size() + 1];
int i = 0;
for (Environment::iterator it = env.begin();
it != env.end(); it++, i++)
env2[i] = (new string(it->first + "=" + it->second))->c_str();
env2[i] = 0;
/* Dup the log handle into stderr. */
if (dup2(fileno(logFile), STDERR_FILENO) == -1)
throw SysError("cannot pipe standard error into log file");
/* Dup stderr to stdin. */
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
throw SysError("cannot dup stderr into stdout");
/* Make the program executable. !!! hack. */
if (chmod(program.c_str(), 0755))
throw SysError("cannot make program executable");
/* Execute the program. This should not return. */
execle(program.c_str(), baseNameOf(program).c_str(), 0, env2);
throw SysError(format("unable to execute %1%") % program);
} catch (exception & e) {
cerr << format("build error: %1%\n") % e.what();
}
_exit(1);
}
/* parent */
/* Close the logging pipe. Note that this should not cause
the logger to exit until builder exits (because the latter
has an open file handle to the former). */
pclose(logFile);
/* Wait for the child to finish. */
int status;
if (waitpid(pid, &status, 0) != pid)
throw Error("unable to wait for child");
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
delTmpDir.cancel();
throw Error("unable to build package");
}
}
/* Throw an exception if the given platform string is not supported by
the platform we are executing on. */
static void checkPlatform(const string & platform)
{
if (platform != thisSystem)
throw Error(format("a `%1%' is required, but I am a `%2%'")
% platform % thisSystem);
}
string printTerm(ATerm t)
@ -157,23 +22,16 @@ Hash hashTerm(ATerm t)
}
FState hash2fstate(Hash hash)
{
return ATmake("Include(<str>)", ((string) hash).c_str());
}
ATerm termFromId(const FSId & id, string * p)
ATerm termFromId(const FSId & id)
{
string path = expandId(id);
if (p) *p = path;
ATerm t = ATreadFromNamedFile(path.c_str());
if (!t) throw Error(format("cannot read aterm from `%1%'") % path);
return t;
}
FSId writeTerm(ATerm t, const string & suffix, string * p)
FSId writeTerm(ATerm t, const string & suffix)
{
FSId id = hashTerm(t);
@ -182,28 +40,14 @@ FSId writeTerm(ATerm t, const string & suffix, string * p)
if (!ATwriteToNamedTextFile(t, path.c_str()))
throw Error(format("cannot write aterm %1%") % path);
// debug(format("written term %1% = %2%") % (string) id %
// printTerm(t));
registerPath(path, id);
if (p) *p = path;
return id;
}
void registerSuccessor(const FSId & id1, const FSId & id2)
{
setDB(nixDB, dbSuccessors, id1, id2);
}
static FSId storeSuccessor(const FSId & id1, FState sc,
string * p)
{
FSId id2 = writeTerm(sc, "-s-" + (string) id1, p);
registerSuccessor(id1, id2);
return id2;
}
static void parseIds(ATermList ids, FSIds & out)
{
while (!ATisEmpty(ids)) {
@ -217,251 +61,9 @@ static void parseIds(ATermList ids, FSIds & out)
}
static void checkSlice(const Slice & slice);
/* Parse a slice. */
static Slice parseSlice(FState fs)
{
Slice slice;
ATermList roots, elems;
if (!ATmatch(fs, "Slice([<list>], [<list>])", &roots, &elems))
throw badTerm("not a slice", fs);
parseIds(roots, slice.roots);
while (!ATisEmpty(elems)) {
char * s1, * s2;
ATermList refs;
ATerm t = ATgetFirst(elems);
if (!ATmatch(t, "(<str>, <str>, [<list>])", &s1, &s2, &refs))
throw badTerm("not a slice element", t);
SliceElem elem;
elem.path = s1;
elem.id = parseHash(s2);
parseIds(refs, elem.refs);
slice.elems.push_back(elem);
elems = ATgetNext(elems);
}
checkSlice(slice);
return slice;
}
static ATermList unparseIds(const FSIds & ids)
{
ATermList l = ATempty;
for (FSIds::const_iterator i = ids.begin();
i != ids.end(); i++)
l = ATinsert(l,
ATmake("<str>", ((string) *i).c_str()));
return ATreverse(l);
}
static FState unparseSlice(const Slice & slice)
{
ATermList roots = unparseIds(slice.roots);
ATermList elems = ATempty;
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
elems = ATinsert(elems,
ATmake("(<str>, <str>, <term>)",
i->path.c_str(),
((string) i->id).c_str(),
unparseIds(i->refs)));
return ATmake("Slice(<term>, <term>)", roots, elems);
}
typedef set<FSId> FSIdSet;
static Slice normaliseFState2(FSId id, StringSet & usedPaths)
{
debug(format("normalising fstate"));
Nest nest(true);
/* Try to substitute $id$ by any known successors in order to
speed up the rewrite process. */
string idSucc;
while (queryDB(nixDB, dbSuccessors, id, idSucc)) {
debug(format("successor %1% -> %2%") % (string) id % idSucc);
id = parseHash(idSucc);
}
/* Get the fstate expression. */
string fsPath;
FState fs = termFromId(id, &fsPath);
/* Already in normal form (i.e., a slice)? */
if (ATgetType(fs) == AT_APPL &&
(string) ATgetName(ATgetAFun(fs)) == "Slice")
{
usedPaths.insert(fsPath);
return parseSlice(fs);
}
/* Then we it's a Derive node. */
ATermList outs, ins, bnds;
char * builder;
char * platform;
if (!ATmatch(fs, "Derive([<list>], [<list>], <str>, <str>, [<list>])",
&outs, &ins, &builder, &platform, &bnds))
throw badTerm("not a derive", fs);
/* Right platform? */
checkPlatform(platform);
/* Realise inputs (and remember all input paths). */
FSIds inIds;
parseIds(ins, inIds);
typedef map<string, SliceElem> ElemMap;
ElemMap inMap;
for (FSIds::iterator i = inIds.begin(); i != inIds.end(); i++) {
Slice slice = normaliseFState(*i);
realiseSlice(slice);
for (SliceElems::iterator j = slice.elems.begin();
j != slice.elems.end(); j++)
inMap[j->path] = *j;
}
Strings inPaths;
for (ElemMap::iterator i = inMap.begin(); i != inMap.end(); i++)
inPaths.push_back(i->second.path);
/* Build the environment. */
Environment env;
while (!ATisEmpty(bnds)) {
char * s1, * s2;
ATerm bnd = ATgetFirst(bnds);
if (!ATmatch(bnd, "(<str>, <str>)", &s1, &s2))
throw badTerm("tuple of strings expected", bnd);
env[s1] = s2;
bnds = ATgetNext(bnds);
}
/* Parse the outputs. */
typedef map<string, FSId> OutPaths;
OutPaths outPaths;
while (!ATisEmpty(outs)) {
ATerm t = ATgetFirst(outs);
char * s1, * s2;
if (!ATmatch(t, "(<str>, <str>)", &s1, &s2))
throw badTerm("string expected", t);
outPaths[s1] = parseHash(s2);
inPaths.push_back(s1);
outs = ATgetNext(outs);
}
/* We can skip running the builder if we can expand all output
paths from their ids. */
bool fastBuild = false;
#if 0
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
try {
expandId(i->second, i->first);
} catch (...) {
fastBuild = false;
break;
}
}
#endif
if (!fastBuild) {
/* Check that none of the outputs exist. */
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
if (pathExists(i->first))
throw Error(format("path `%1%' exists") % i->first);
/* Run the builder. */
runProgram(builder, env);
} else
debug(format("skipping build"));
Slice slice;
/* Check whether the output paths were created, and register each
one. */
FSIdSet used;
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
string path = i->first;
if (!pathExists(path))
throw Error(format("path `%1%' does not exist") % path);
registerPath(path, i->second);
slice.roots.push_back(i->second);
Strings refs = filterReferences(path, inPaths);
SliceElem elem;
elem.path = path;
elem.id = i->second;
for (Strings::iterator j = refs.begin(); j != refs.end(); j++) {
ElemMap::iterator k;
OutPaths::iterator l;
if ((k = inMap.find(*j)) != inMap.end()) {
elem.refs.push_back(k->second.id);
used.insert(k->second.id);
for (FSIds::iterator m = k->second.refs.begin();
m != k->second.refs.end(); m++)
used.insert(*m);
} else if ((l = outPaths.find(*j)) != outPaths.end()) {
elem.refs.push_back(l->second);
used.insert(l->second);
} else
throw Error(format("unknown referenced path `%1%'") % *j);
}
slice.elems.push_back(elem);
}
for (ElemMap::iterator i = inMap.begin();
i != inMap.end(); i++)
{
FSIdSet::iterator j = used.find(i->second.id);
if (j == used.end())
debug(format("NOT referenced: `%1%'") % i->second.path);
else {
debug(format("referenced: `%1%'") % i->second.path);
slice.elems.push_back(i->second);
}
}
FState nf = unparseSlice(slice);
debug(printTerm(nf));
storeSuccessor(id, nf, &fsPath);
usedPaths.insert(fsPath);
parseSlice(nf); /* check */
return slice;
}
Slice normaliseFState(FSId id)
{
StringSet dummy;
return normaliseFState2(id, dummy);
}
static void checkSlice(const Slice & slice)
{
if (slice.elems.size() == 0)
@ -486,97 +88,142 @@ static void checkSlice(const Slice & slice)
}
void realiseSlice(const Slice & slice)
/* Parse a slice. */
static bool parseSlice(ATerm t, Slice & slice)
{
debug(format("realising slice"));
Nest nest(true);
ATermList roots, elems;
/* Perhaps all paths already contain the right id? */
if (!ATmatch(t, "Slice([<list>], [<list>])", &roots, &elems))
return false;
bool missing = false;
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
{
SliceElem elem = *i;
string id;
if (!queryDB(nixDB, dbPath2Id, elem.path, id)) {
if (pathExists(elem.path))
throw Error(format("path `%1%' obstructed") % elem.path);
missing = true;
break;
}
if (parseHash(id) != elem.id)
throw Error(format("path `%1%' obstructed") % elem.path);
parseIds(roots, slice.roots);
while (!ATisEmpty(elems)) {
char * s1, * s2;
ATermList refs;
ATerm t = ATgetFirst(elems);
if (!ATmatch(t, "(<str>, <str>, [<list>])", &s1, &s2, &refs))
throw badTerm("not a slice element", t);
SliceElem elem;
elem.path = s1;
elem.id = parseHash(s2);
parseIds(refs, elem.refs);
slice.elems.push_back(elem);
elems = ATgetNext(elems);
}
if (!missing) {
debug(format("already installed"));
return;
}
/* For each element, expand its id at its path. */
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
{
SliceElem elem = *i;
expandId(elem.id, elem.path);
}
checkSlice(slice);
return true;
}
Strings fstatePaths(const FSId & id, bool normalise)
static bool parseDerive(ATerm t, Derive & derive)
{
Strings paths;
FState fs = termFromId(id);
ATermList outs, ins, bnds;
char * builder;
char * platform;
if (normalise ||
(ATgetType(fs) == AT_APPL &&
(string) ATgetName(ATgetAFun(fs)) == "Slice"))
{
Slice slice;
if (normalise)
slice = normaliseFState(id);
else
slice = parseSlice(fs);
/* !!! fix complexity */
for (FSIds::const_iterator i = slice.roots.begin();
i != slice.roots.end(); i++)
for (SliceElems::const_iterator j = slice.elems.begin();
j != slice.elems.end(); j++)
if (*i == j->id) paths.push_back(j->path);
}
else if (ATmatch(fs, "Derive([<list>], [<list>], <str>, <str>, [<list>])",
if (!ATmatch(t, "Derive([<list>], [<list>], <str>, <str>, [<list>])",
&outs, &ins, &builder, &platform, &bnds))
{
return false;
while (!ATisEmpty(outs)) {
ATerm t = ATgetFirst(outs);
char * s1, * s2;
ATerm t = ATgetFirst(outs);
if (!ATmatch(t, "(<str>, <str>)", &s1, &s2))
throw badTerm("string expected", t);
paths.push_back(s1);
throw badTerm("not a derive output", t);
derive.outputs.push_back(DeriveOutput(s1, parseHash(s2)));
outs = ATgetNext(outs);
}
parseIds(ins, derive.inputs);
derive.builder = builder;
derive.platform = platform;
while (!ATisEmpty(bnds)) {
char * s1, * s2;
ATerm bnd = ATgetFirst(bnds);
if (!ATmatch(bnd, "(<str>, <str>)", &s1, &s2))
throw badTerm("tuple of strings expected", bnd);
derive.env.push_back(StringPair(s1, s2));
bnds = ATgetNext(bnds);
}
else throw badTerm("in fstatePaths", fs);
return paths;
return true;
}
StringSet fstateRefs(const FSId & id)
FState parseFState(ATerm t)
{
StringSet paths;
Slice slice = normaliseFState2(id, paths);
FState fs;
if (parseSlice(t, fs.slice))
fs.type = FState::fsSlice;
else if (parseDerive(t, fs.derive))
fs.type = FState::fsDerive;
else throw badTerm("not an fstate-expression", t);
return fs;
}
static ATermList unparseIds(const FSIds & ids)
{
ATermList l = ATempty;
for (FSIds::const_iterator i = ids.begin();
i != ids.end(); i++)
l = ATinsert(l,
ATmake("<str>", ((string) *i).c_str()));
return ATreverse(l);
}
static ATerm unparseSlice(const Slice & slice)
{
ATermList roots = unparseIds(slice.roots);
ATermList elems = ATempty;
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
paths.insert(i->path);
return paths;
elems = ATinsert(elems,
ATmake("(<str>, <str>, <term>)",
i->path.c_str(),
((string) i->id).c_str(),
unparseIds(i->refs)));
return ATmake("Slice(<term>, <term>)", roots, elems);
}
static ATerm unparseDerive(const Derive & derive)
{
ATermList outs = ATempty;
for (DeriveOutputs::const_iterator i = derive.outputs.begin();
i != derive.outputs.end(); i++)
outs = ATinsert(outs,
ATmake("(<str>, <str>)",
i->first.c_str(), ((string) i->second).c_str()));
ATermList env = ATempty;
for (StringPairs::const_iterator i = derive.env.begin();
i != derive.env.end(); i++)
env = ATinsert(env,
ATmake("(<str>, <str>)",
i->first.c_str(), i->second.c_str()));
return ATmake("Derive(<term>, <term>, <str>, <str>, <term>)",
ATreverse(outs),
unparseIds(derive.inputs),
derive.builder.c_str(),
derive.platform.c_str(),
ATreverse(env));
}
ATerm unparseFState(const FState & fs)
{
if (fs.type == FState::fsSlice)
return unparseSlice(fs.slice);
else if (fs.type == FState::fsDerive)
return unparseDerive(fs.derive);
else abort();
}

89
src/fstate.hh
View file

@ -5,55 +5,13 @@ extern "C" {
#include <aterm2.h>
}
#include "hash.hh"
#include "store.hh"
using namespace std;
/* \section{Abstract syntax of Nix file system state expressions}
A Nix file system state expression, or FState, describes a
(partial) state of the file system.
Slice : [Id] * [(Path, Id, [Id])] -> FState
(update)
Path(path, content, refs) specifies a file object (its full path
and contents), along with all file objects referenced by it (that
is, that it has pointers to). We assume that all files are
self-referential. This prevents us from having to deal with
cycles.
Derive : [(Path, Id)] * [FStateId] * Path * [(String, String)] -> FState
(update)
Derive(platform, builder, ins, outs, env) specifies the creation of
new file objects (in paths declared by `outs') by the execution of
a program `builder' on a platform `platform'. This execution takes
place in a file system state given by `ins'. `env' specifies a
mapping of strings to strings.
A FState expression is in {\em $f$-normal form} if all Derive nodes
have been reduced to File nodes.
DISCUSSION: the idea is that a Regular/Directory is interchangeable
with its CHash. This would appear to break referential
transparency, e.g., Derive(..., ..., [...CHash(h)...], ...) can
only be reduced in a context were the Regular/Directory equivalent
of Hash(h) is known. However, CHash should be viewed strictly as a
shorthand; that is, when we export an expression containing a
CHash, we should also export the file object referenced by that
CHash.
*/
typedef ATerm FState;
typedef ATerm Content;
/* Abstract syntax of fstate-expressions. */
typedef list<FSId> FSIds;
struct SliceElem
{
string path;
@ -69,6 +27,27 @@ struct Slice
SliceElems elems;
};
typedef pair<string, FSId> DeriveOutput;
typedef pair<string, string> StringPair;
typedef list<DeriveOutput> DeriveOutputs;
typedef list<StringPair> StringPairs;
struct Derive
{
DeriveOutputs outputs;
FSIds inputs;
string builder;
string platform;
StringPairs env;
};
struct FState
{
enum { fsSlice, fsDerive } type;
Slice slice;
Derive derive;
};
/* Return a canonical textual representation of an expression. */
string printTerm(ATerm t);
@ -81,28 +60,16 @@ Error badTerm(const format & f, ATerm t);
Hash hashTerm(ATerm t);
/* Read an aterm from disk, given its id. */
ATerm termFromId(const FSId & id, string * p = 0);
ATerm termFromId(const FSId & id);
/* Write an aterm to the Nix store directory, and return its hash. */
FSId writeTerm(ATerm t, const string & suffix, string * p = 0);
FSId writeTerm(ATerm t, const string & suffix);
/* Register a successor. */
void registerSuccessor(const FSId & id1, const FSId & id2);
/* Parse an fstate-expression. */
FState parseFState(ATerm t);
/* Normalise an fstate-expression, that is, return an equivalent
Slice. */
Slice normaliseFState(FSId id);
/* Realise a Slice in the file system. */
void realiseSlice(const Slice & slice);
/* Get the list of root (output) paths of the given
fstate-expression. */
Strings fstatePaths(const FSId & id, bool normalise);
/* Get the list of paths referenced by the given fstate-expression. */
StringSet fstateRefs(const FSId & id);
/* Parse an fstate-expression. */
ATerm unparseFState(const FState & fs);
#endif /* !__FSTATE_H */

3
src/nix.cc
View file

@ -1,8 +1,7 @@
#include <iostream>
#include "globals.hh"
#include "store.hh"
#include "fstate.hh"
#include "normalise.hh"
#include "archive.hh"
#include "shared.hh"

265
src/normalise.cc Normal file
View file

@ -0,0 +1,265 @@
#include <map>
#include "normalise.hh"
#include "references.hh"
#include "db.hh"
#include "exec.hh"
#include "globals.hh"
void registerSuccessor(const FSId & id1, const FSId & id2)
{
setDB(nixDB, dbSuccessors, id1, id2);
}
static FSId storeSuccessor(const FSId & id1, ATerm sc)
{
FSId id2 = writeTerm(sc, "-s-" + (string) id1);
registerSuccessor(id1, id2);
return id2;
}
typedef set<FSId> FSIdSet;
Slice normaliseFState(FSId id)
{
debug(format("normalising fstate %1%") % (string) id);
Nest nest(true);
/* Try to substitute $id$ by any known successors in order to
speed up the rewrite process. */
string idSucc;
while (queryDB(nixDB, dbSuccessors, id, idSucc)) {
debug(format("successor %1% -> %2%") % (string) id % idSucc);
id = parseHash(idSucc);
}
/* Get the fstate expression. */
FState fs = parseFState(termFromId(id));
/* It this is a normal form (i.e., a slice) we are done. */
if (fs.type == FState::fsSlice) return fs.slice;
/* Otherwise, it's a derivation. */
/* Right platform? */
if (fs.derive.platform != thisSystem)
throw Error(format("a `%1%' is required, but I am a `%2%'")
% fs.derive.platform % thisSystem);
/* Realise inputs (and remember all input paths). */
typedef map<string, SliceElem> ElemMap;
ElemMap inMap;
for (FSIds::iterator i = fs.derive.inputs.begin();
i != fs.derive.inputs.end(); i++) {
Slice slice = normaliseFState(*i);
realiseSlice(slice);
for (SliceElems::iterator j = slice.elems.begin();
j != slice.elems.end(); j++)
inMap[j->path] = *j;
}
Strings inPaths;
for (ElemMap::iterator i = inMap.begin(); i != inMap.end(); i++)
inPaths.push_back(i->second.path);
/* Build the environment. */
Environment env;
for (StringPairs::iterator i = fs.derive.env.begin();
i != fs.derive.env.end(); i++)
env[i->first] = i->second;
/* Parse the outputs. */
typedef map<string, FSId> OutPaths;
OutPaths outPaths;
for (DeriveOutputs::iterator i = fs.derive.outputs.begin();
i != fs.derive.outputs.end(); i++)
{
debug(format("building %1% in %2%") % (string) i->second % i->first);
outPaths[i->first] = i->second;
inPaths.push_back(i->first);
}
/* We can skip running the builder if we can expand all output
paths from their ids. */
bool fastBuild = false;
#if 0
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
try {
expandId(i->second, i->first);
} catch (...) {
fastBuild = false;
break;
}
}
#endif
if (!fastBuild) {
/* Check that none of the outputs exist. */
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
if (pathExists(i->first))
throw Error(format("path `%1%' exists") % i->first);
/* Run the builder. */
debug(format("building..."));
runProgram(fs.derive.builder, env);
debug(format("build completed"));
} else
debug(format("skipping build"));
/* Check whether the output paths were created, and register each
one. */
FSIdSet used;
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
string path = i->first;
if (!pathExists(path))
throw Error(format("path `%1%' does not exist") % path);
registerPath(path, i->second);
fs.slice.roots.push_back(i->second);
Strings refs = filterReferences(path, inPaths);
SliceElem elem;
elem.path = path;
elem.id = i->second;
for (Strings::iterator j = refs.begin(); j != refs.end(); j++) {
ElemMap::iterator k;
OutPaths::iterator l;
if ((k = inMap.find(*j)) != inMap.end()) {
elem.refs.push_back(k->second.id);
used.insert(k->second.id);
for (FSIds::iterator m = k->second.refs.begin();
m != k->second.refs.end(); m++)
used.insert(*m);
} else if ((l = outPaths.find(*j)) != outPaths.end()) {
elem.refs.push_back(l->second);
used.insert(l->second);
} else
throw Error(format("unknown referenced path `%1%'") % *j);
}
fs.slice.elems.push_back(elem);
}
for (ElemMap::iterator i = inMap.begin();
i != inMap.end(); i++)
{
FSIdSet::iterator j = used.find(i->second.id);
if (j == used.end())
debug(format("NOT referenced: `%1%'") % i->second.path);
else {
debug(format("referenced: `%1%'") % i->second.path);
fs.slice.elems.push_back(i->second);
}
}
fs.type = FState::fsSlice;
ATerm nf = unparseFState(fs);
debug(format("normal form: %1%") % printTerm(nf));
storeSuccessor(id, nf);
return fs.slice;
}
void realiseSlice(const Slice & slice)
{
debug(format("realising slice"));
Nest nest(true);
/* Perhaps all paths already contain the right id? */
bool missing = false;
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
{
SliceElem elem = *i;
string id;
if (!queryDB(nixDB, dbPath2Id, elem.path, id)) {
if (pathExists(elem.path))
throw Error(format("path `%1%' obstructed") % elem.path);
missing = true;
break;
}
if (parseHash(id) != elem.id)
throw Error(format("path `%1%' obstructed") % elem.path);
}
if (!missing) {
debug(format("already installed"));
return;
}
/* For each element, expand its id at its path. */
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
{
SliceElem elem = *i;
debug(format("expanding %1% in %2%") % (string) elem.id % elem.path);
expandId(elem.id, elem.path);
}
}
Strings fstatePaths(const FSId & id, bool normalise)
{
Strings paths;
FState fs;
if (normalise) {
fs.slice = normaliseFState(id);
fs.type = FState::fsSlice;
} else
fs = parseFState(termFromId(id));
if (fs.type == FState::fsSlice) {
/* !!! fix complexity */
for (FSIds::const_iterator i = fs.slice.roots.begin();
i != fs.slice.roots.end(); i++)
for (SliceElems::const_iterator j = fs.slice.elems.begin();
j != fs.slice.elems.end(); j++)
if (*i == j->id) paths.push_back(j->path);
}
else if (fs.type == FState::fsDerive) {
for (DeriveOutputs::iterator i = fs.derive.outputs.begin();
i != fs.derive.outputs.end(); i++)
paths.push_back(i->first);
}
else abort();
return paths;
}
StringSet fstateRefs(const FSId & id)
{
StringSet paths;
Slice slice = normaliseFState(id);
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
paths.insert(i->path);
return paths;
}
void findGenerators(const FSIds & ids)
{
}

25
src/normalise.hh Normal file
View file

@ -0,0 +1,25 @@
#ifndef __NORMALISE_H
#define __NORMALISE_H
#include "fstate.hh"
/* Normalise an fstate-expression, that is, return an equivalent
Slice. */
Slice normaliseFState(FSId id);
/* Realise a Slice in the file system. */
void realiseSlice(const Slice & slice);
/* Get the list of root (output) paths of the given
fstate-expression. */
Strings fstatePaths(const FSId & id, bool normalise);
/* Get the list of paths referenced by the given fstate-expression. */
StringSet fstateRefs(const FSId & id);
/* Register a successor. */
void registerSuccessor(const FSId & id1, const FSId & id2);
#endif /* !__NORMALISE_H */

BIN
src/normalise.o Normal file
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2
src/store.cc
View file

@ -7,7 +7,7 @@
#include "globals.hh"
#include "db.hh"
#include "archive.hh"
#include "fstate.hh"
#include "normalise.hh"
struct CopySink : DumpSink

37
src/test.cc
View file

@ -6,14 +6,14 @@
#include "hash.hh"
#include "archive.hh"
#include "util.hh"
#include "fstate.hh"
#include "store.hh"
#include "normalise.hh"
#include "globals.hh"
void realise(FSId id)
{
cout << format("realising %1%\n") % (string) id;
debug(format("TEST: realising %1%") % (string) id);
Nest nest(true);
Slice slice = normaliseFState(id);
realiseSlice(slice);
}
@ -117,7 +117,7 @@ void runTests()
string builder1fn;
addToStore("./test-builder-1.sh", builder1fn, builder1id);
FState fs1 = ATmake(
ATerm fs1 = ATmake(
"Slice([<str>], [(<str>, <str>, [])])",
((string) builder1id).c_str(),
builder1fn.c_str(),
@ -127,7 +127,7 @@ void runTests()
realise(fs1id);
realise(fs1id);
FState fs2 = ATmake(
ATerm fs2 = ATmake(
"Slice([<str>], [(<str>, <str>, [])])",
((string) builder1id).c_str(),
(builder1fn + "_bla").c_str(),
@ -139,7 +139,7 @@ void runTests()
string out1id = hashString("foo"); /* !!! bad */
string out1fn = nixStore + "/" + (string) out1id + "-hello.txt";
FState fs3 = ATmake(
ATerm fs3 = ATmake(
"Derive([(<str>, <str>)], [<str>], <str>, <str>, [(\"out\", <str>)])",
out1fn.c_str(),
((string) out1id).c_str(),
@ -158,7 +158,7 @@ void runTests()
string builder4fn;
addToStore("./test-builder-2.sh", builder4fn, builder4id);
FState fs4 = ATmake(
ATerm fs4 = ATmake(
"Slice([<str>], [(<str>, <str>, [])])",
((string) builder4id).c_str(),
builder4fn.c_str(),
@ -169,7 +169,7 @@ void runTests()
string out5id = hashString("bar"); /* !!! bad */
string out5fn = nixStore + "/" + (string) out5id + "-hello2";
FState fs5 = ATmake(
ATerm fs5 = ATmake(
"Derive([(<str>, <str>)], [<str>], <str>, <str>, [(\"out\", <str>), (\"builder\", <str>)])",
out5fn.c_str(),
((string) out5id).c_str(),
@ -183,27 +183,6 @@ void runTests()
realise(fs5id);
realise(fs5id);
#if 0
FState fs2 = ATmake(
"Path(<str>, Hash(<str>), [])",
(builder1fn + "_bla").c_str(),
((string) builder1h).c_str());
realise(fs2);
realise(fs2);
string out1fn = nixStore + "/hello.txt";
FState fs3 = ATmake(
"Derive(<str>, <str>, [<term>], <str>, [(\"out\", <str>)])",
thisSystem.c_str(),
builder1fn.c_str(),
fs1,
out1fn.c_str(),
out1fn.c_str());
realise(fs3);
#endif
}

2
src/util.cc
View file

@ -150,7 +150,7 @@ void msg(const format & f)
{
string spaces;
for (int i = 0; i < nestingLevel; i++)
spaces += " ";
spaces += "| ";
cerr << format("%1%%2%\n") % spaces % f.str();
}

8
substitute.mk Normal file
View file

@ -0,0 +1,8 @@
%: %.in Makefile
sed \
-e s^@prefix\@^$(prefix)^g \
-e s^@bindir\@^$(bindir)^g \
-e s^@sysconfdir\@^$(sysconfdir)^g \
-e s^@localstatedir\@^$(localstatedir)^g \
< $< > $@ || rm $@
chmod +x $@