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* For efficiency: md5 integrated into nix.

Browse source 
* Command `nix ensure' which is like `nix getpkg' except that if the
  has refers to a run action it will just ensure that the imports are
  there.
* Command `nix closure' to print out the closure of the set of
  descriptors under the import relation, starting at a set of roots.
  This can be used for garbage collection (e.g., given a list of
  `activated' packages, we can delete all packages not reachable from
  those).
* Command `nix graph' to print out a Dot graph of the dependency
  graph.
* `nix-addroot' adds a root for the (unimplemented) garbage collector.
This commit is contained in:
Eelco Dolstra 2003-03-24 17:49:56 +00:00
parent eeab86e0ac
commit 73c53935d0
5 changed files with 810 additions and 66 deletions
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260
src/nix.cc
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@ -4,6 +4,8 @@
#include <string>
#include <sstream>
#include <list>
#include <vector>
#include <set>
#include <map>
#include <cstdio>
@ -14,6 +16,10 @@
#include <db4/db_cxx.h>
extern "C" {
#include "md5.h"
}
using namespace std;
@ -146,8 +152,20 @@ void enumDB(const string & dbname, DBPairs & contents)
}
string printHash(unsigned char * buf)
{
ostringstream str;
for (int i = 0; i < 16; i++) {
str.fill('0');
str.width(2);
str << hex << (int) buf[i];
}
return str.str();
}
/* Verify that a reference is valid (that is, is a MD5 hash code). */
void checkRef(const string & s)
void checkHash(const string & s)
{
string err = "invalid reference: " + s;
if (s.length() != 32)
@ -162,31 +180,36 @@ void checkRef(const string & s)
/* Compute the MD5 hash of a file. */
string makeRef(string filename)
string hashFile(string filename)
{
char hash[33];
FILE * pipe = popen(("md5sum " + filename + " 2> /dev/null").c_str(), "r");
if (!pipe) throw BadRefError("cannot execute md5sum");
if (fread(hash, 32, 1, pipe) != 1)
throw BadRefError("cannot read hash from md5sum of " + filename);
hash[32] = 0;
pclose(pipe);
checkRef(hash);
return hash;
unsigned char hash[16];
FILE * file = fopen(filename.c_str(), "rb");
if (!file)
throw BadRefError("file `" + filename + "' does not exist");
int err = md5_stream(file, hash);
fclose(file);
if (err) throw BadRefError("cannot hash file");
return printHash(hash);
}
typedef pair<string, string> Param;
typedef list<Param> Params;
typedef map<string, string> Params;
void readPkgDescr(const string & pkgfile,
void readPkgDescr(const string & hash,
Params & pkgImports, Params & fileImports, Params & arguments)
{
string pkgfile;
if (!queryDB(dbRefs, hash, pkgfile))
throw Error("unknown package " + hash);
// cerr << "reading information about " + hash + " from " + pkgfile + "\n";
/* Verify that the file hasn't changed. !!! race */
if (hashFile(pkgfile) != hash)
throw Error("file " + pkgfile + " is stale");
ifstream file;
file.exceptions(ios::badbit);
file.open(pkgfile.c_str());
@ -206,13 +229,13 @@ void readPkgDescr(const string & pkgfile,
str >> name >> op >> ref;
if (op == "<-") {
checkRef(ref);
pkgImports.push_back(Param(name, ref));
checkHash(ref);
pkgImports[name] = ref;
} else if (op == "=") {
checkRef(ref);
fileImports.push_back(Param(name, ref));
checkHash(ref);
fileImports[name] = ref;
} else if (op == ":")
arguments.push_back(Param(name, ref));
arguments[name] = ref;
else throw Error("invalid operator " + op);
}
}
@ -226,20 +249,9 @@ typedef map<string, string> Environment;
void fetchDeps(string hash, Environment & env)
{
string pkgfile;
if (!queryDB(dbRefs, hash, pkgfile))
throw Error("unknown package " + hash);
cerr << "reading information about " + hash + " from " + pkgfile + "\n";
/* Verify that the file hasn't changed. !!! race */
if (makeRef(pkgfile) != hash)
throw Error("file " + pkgfile + " is stale");
/* Read the package description file. */
Params pkgImports, fileImports, arguments;
readPkgDescr(pkgfile, pkgImports, fileImports, arguments);
readPkgDescr(hash, pkgImports, fileImports, arguments);
/* Recursively fetch all the dependencies, filling in the
environment as we go along. */
@ -264,7 +276,7 @@ void fetchDeps(string hash, Environment & env)
if (!queryDB(dbRefs, it->second, file))
throw Error("unknown file " + it->second);
if (makeRef(file) != it->second)
if (hashFile(file) != it->second)
throw Error("file " + file + " is stale");
env[it->first] = file;
@ -374,7 +386,7 @@ void installPkg(string hash)
string getPkg(string hash)
{
string path;
checkRef(hash);
checkHash(hash);
while (!queryDB(dbInstPkgs, hash, path))
installPkg(hash);
return path;
@ -434,6 +446,20 @@ void runPkg(string hash)
}
void ensurePkg(string hash)
{
Params pkgImports, fileImports, arguments;
readPkgDescr(hash, pkgImports, fileImports, arguments);
if (fileImports.find("build") != fileImports.end())
getPkg(hash);
else if (fileImports.find("run") != fileImports.end()) {
Environment env;
fetchDeps(hash, env);
} else throw Error("invalid descriptor");
}
string absPath(string filename)
{
if (filename[0] != '/') {
@ -450,14 +476,14 @@ string absPath(string filename)
void registerFile(string filename)
{
filename = absPath(filename);
setDB(dbRefs, makeRef(filename), filename);
setDB(dbRefs, hashFile(filename), filename);
}
/* This is primarily used for bootstrapping. */
void registerInstalledPkg(string hash, string path)
{
checkRef(hash);
checkHash(hash);
if (path == "")
delDB(dbInstPkgs, hash);
else
@ -483,8 +509,10 @@ void verifyDB()
it != fileRefs.end(); it++)
{
try {
if (makeRef(it->second) != it->first)
if (hashFile(it->second) != it->first) {
cerr << "file " << it->second << " has changed\n";
delDB(dbRefs, it->first);
}
} catch (BadRefError e) { /* !!! better error check */
cerr << "file " << it->second << " has disappeared\n";
delDB(dbRefs, it->first);
@ -519,48 +547,136 @@ void listInstalledPkgs()
for (DBPairs::iterator it = instPkgs.begin();
it != instPkgs.end(); it++)
cout << it->first << endl;
}
void printInfo(vector<string> hashes)
{
for (vector<string>::iterator it = hashes.begin();
it != hashes.end(); it++)
{
string descr;
if (!queryDB(dbRefs, it->first, descr))
descr = "descriptor missing";
cout << it->first << " " << descr << endl;
try {
Params pkgImports, fileImports, arguments;
readPkgDescr(*it, pkgImports, fileImports, arguments);
cout << *it << " " << getFromEnv(arguments, "id") << endl;
} catch (Error & e) {
cout << *it << " (descriptor missing)\n";
}
}
}
void run(int argc, char * * argv)
void computeClosure(const vector<string> & rootHashes,
set<string> & result)
{
list<string> workList(rootHashes.begin(), rootHashes.end());
set<string> doneSet;
while (!workList.empty()) {
string hash = workList.front();
workList.pop_front();
if (doneSet.find(hash) == doneSet.end()) {
doneSet.insert(hash);
Params pkgImports, fileImports, arguments;
readPkgDescr(hash, pkgImports, fileImports, arguments);
for (Params::iterator it = pkgImports.begin();
it != pkgImports.end(); it++)
workList.push_back(it->second);
}
}
result = doneSet;
}
void printClosure(const vector<string> & rootHashes)
{
set<string> allHashes;
computeClosure(rootHashes, allHashes);
for (set<string>::iterator it = allHashes.begin();
it != allHashes.end(); it++)
cout << *it << endl;
}
string dotQuote(const string & s)
{
return "\"" + s + "\"";
}
void printGraph(vector<string> rootHashes)
{
set<string> allHashes;
computeClosure(rootHashes, allHashes);
cout << "digraph G {\n";
for (set<string>::iterator it = allHashes.begin();
it != allHashes.end(); it++)
{
Params pkgImports, fileImports, arguments;
readPkgDescr(*it, pkgImports, fileImports, arguments);
cout << dotQuote(*it) << "[label = \""
<< getFromEnv(arguments, "id")
<< "\"];\n";
for (Params::iterator it2 = pkgImports.begin();
it2 != pkgImports.end(); it2++)
cout << dotQuote(it2->second) << " -> "
<< dotQuote(*it) << ";\n";
}
cout << "}\n";
}
void run(vector<string> args)
{
UsageError argcError("wrong number of arguments");
string cmd;
if (argc < 1)
throw UsageError("no command specified");
cmd = argv[0];
argc--, argv++;
if (args.size() < 1) throw UsageError("no command specified");
cmd = args[0];
args.erase(args.begin()); // O(n)
if (cmd == "init") {
if (argc != 0) throw argcError;
if (args.size() != 0) throw argcError;
initDB();
} else if (cmd == "verify") {
if (argc != 0) throw argcError;
if (args.size() != 0) throw argcError;
verifyDB();
} else if (cmd == "getpkg") {
if (argc != 1) throw argcError;
string path = getPkg(argv[0]);
if (args.size() != 1) throw argcError;
string path = getPkg(args[0]);
cout << path << endl;
} else if (cmd == "run") {
if (argc != 1) throw argcError;
runPkg(argv[0]);
if (args.size() != 1) throw argcError;
runPkg(args[0]);
} else if (cmd == "ensure") {
if (args.size() != 1) throw argcError;
ensurePkg(args[0]);
} else if (cmd == "regfile") {
if (argc != 1) throw argcError;
registerFile(argv[0]);
if (args.size() != 1) throw argcError;
registerFile(args[0]);
} else if (cmd == "reginst") {
if (argc != 2) throw argcError;
registerInstalledPkg(argv[0], argv[1]);
if (args.size() != 2) throw argcError;
registerInstalledPkg(args[0], args[1]);
} else if (cmd == "listinst") {
if (argc != 0) throw argcError;
if (args.size() != 0) throw argcError;
listInstalledPkgs();
} else if (cmd == "info") {
printInfo(args);
} else if (cmd == "closure") {
printClosure(args);
} else if (cmd == "graph") {
printGraph(args);
} else
throw UsageError("unknown command: " + string(cmd));
}
@ -594,6 +710,20 @@ Subcommands:
run HASH
Run the descriptor referenced by HASH.
ensure HASH
Like getpkg, but if HASH refers to a run descriptor, fetch only
the dependencies.
info HASH...
Print information about the specified descriptors.
closure HASH...
Determine the closure of the set of descriptors under the import
relation, starting at the given roots.
graph HASH...
Like closure, but print a dot graph specification.
";
}
@ -630,11 +760,13 @@ void main2(int argc, char * * argv)
}
}
argc -= optind, argv += optind;
run(argc, argv);
vector<string> args;
argc--, argv++;
while (argc--) args.push_back(*argv++);
run(args);
}
int main(int argc, char * * argv)
{
prog = argv[0];