Merge branch 'nix' into 'master'.

1 files changed, 331 insertions, 0 deletions

diff --git a/nix/libstore/store-api.cc b/nix/libstore/store-api.cc
new file mode 100644
index 0000000000..0238e5b0b6
--- /dev/null
+++ b/nix/libstore/store-api.cc
@@ -0,0 +1,331 @@
+#include "store-api.hh"
+#include "globals.hh"
+#include "util.hh"
+
+#include <climits>
+
+
+namespace nix {
+
+
+GCOptions::GCOptions()
+{
+    action = gcDeleteDead;
+    ignoreLiveness = false;
+    maxFreed = ULLONG_MAX;
+}
+
+
+bool isInStore(const Path & path)
+{
+    return isInDir(path, settings.nixStore);
+}
+
+
+bool isStorePath(const Path & path)
+{
+    return isInStore(path)
+        && path.find('/', settings.nixStore.size() + 1) == Path::npos;
+}
+
+
+void assertStorePath(const Path & path)
+{
+    if (!isStorePath(path))
+        throw Error(format("path `%1%' is not in the Nix store") % path);
+}
+
+
+Path toStorePath(const Path & path)
+{
+    if (!isInStore(path))
+        throw Error(format("path `%1%' is not in the Nix store") % path);
+    Path::size_type slash = path.find('/', settings.nixStore.size() + 1);
+    if (slash == Path::npos)
+        return path;
+    else
+        return Path(path, 0, slash);
+}
+
+
+Path followLinksToStore(const Path & _path)
+{
+    Path path = absPath(_path);
+    while (!isInStore(path)) {
+        if (!isLink(path)) break;
+        string target = readLink(path);
+        path = absPath(target, dirOf(path));
+    }
+    if (!isInStore(path))
+        throw Error(format("path `%1%' is not in the Nix store") % path);
+    return path;
+}
+
+
+Path followLinksToStorePath(const Path & path)
+{
+    return toStorePath(followLinksToStore(path));
+}
+
+
+string storePathToName(const Path & path)
+{
+    assertStorePath(path);
+    return string(path, settings.nixStore.size() + 34);
+}
+
+
+void checkStoreName(const string & name)
+{
+    string validChars = "+-._?=";
+    /* Disallow names starting with a dot for possible security
+       reasons (e.g., "." and ".."). */
+    if (string(name, 0, 1) == ".")
+        throw Error(format("illegal name: `%1%'") % name);
+    foreach (string::const_iterator, i, name)
+        if (!((*i >= 'A' && *i <= 'Z') ||
+              (*i >= 'a' && *i <= 'z') ||
+              (*i >= '0' && *i <= '9') ||
+              validChars.find(*i) != string::npos))
+        {
+            throw Error(format("invalid character `%1%' in name `%2%'")
+                % *i % name);
+        }
+}
+
+
+/* Store paths have the following form:
+
+   <store>/<h>-<name>
+
+   where
+
+   <store> = the location of the Nix store, usually /nix/store
+   
+   <name> = a human readable name for the path, typically obtained
+     from the name attribute of the derivation, or the name of the
+     source file from which the store path is created.  For derivation
+     outputs other than the default "out" output, the string "-<id>"
+     is suffixed to <name>.
+     
+   <h> = base-32 representation of the first 160 bits of a SHA-256
+     hash of <s>; the hash part of the store name
+     
+   <s> = the string "<type>:sha256:<h2>:<store>:<name>";
+     note that it includes the location of the store as well as the
+     name to make sure that changes to either of those are reflected
+     in the hash (e.g. you won't get /nix/store/<h>-name1 and
+     /nix/store/<h>-name2 with equal hash parts).
+     
+   <type> = one of:
+     "text:<r1>:<r2>:...<rN>"
+       for plain text files written to the store using
+       addTextToStore(); <r1> ... <rN> are the references of the
+       path.
+     "source"
+       for paths copied to the store using addToStore() when recursive
+       = true and hashAlgo = "sha256"
+     "output:<id>"
+       for either the outputs created by derivations, OR paths copied
+       to the store using addToStore() with recursive != true or
+       hashAlgo != "sha256" (in that case "source" is used; it's
+       silly, but it's done that way for compatibility).  <id> is the
+       name of the output (usually, "out").
+
+   <h2> = base-16 representation of a SHA-256 hash of:
+     if <type> = "text:...":
+       the string written to the resulting store path
+     if <type> = "source":
+       the serialisation of the path from which this store path is
+       copied, as returned by hashPath()
+     if <type> = "output:out":
+       for non-fixed derivation outputs:
+         the derivation (see hashDerivationModulo() in
+         primops.cc)
+       for paths copied by addToStore() or produced by fixed-output
+       derivations:
+         the string "fixed:out:<rec><algo>:<hash>:", where
+           <rec> = "r:" for recursive (path) hashes, or "" or flat
+             (file) hashes
+           <algo> = "md5", "sha1" or "sha256"
+           <hash> = base-16 representation of the path or flat hash of
+             the contents of the path (or expected contents of the
+             path for fixed-output derivations)
+
+   It would have been nicer to handle fixed-output derivations under
+   "source", e.g. have something like "source:<rec><algo>", but we're
+   stuck with this for now...
+
+   The main reason for this way of computing names is to prevent name
+   collisions (for security).  For instance, it shouldn't be feasible
+   to come up with a derivation whose output path collides with the
+   path for a copied source.  The former would have a <s> starting with
+   "output:out:", while the latter would have a <2> starting with
+   "source:".
+*/
+
+
+Path makeStorePath(const string & type,
+    const Hash & hash, const string & name)
+{
+    /* e.g., "source:sha256:1abc...:/nix/store:foo.tar.gz" */
+    string s = type + ":sha256:" + printHash(hash) + ":"
+        + settings.nixStore + ":" + name;
+
+    checkStoreName(name);
+
+    return settings.nixStore + "/"
+        + printHash32(compressHash(hashString(htSHA256, s), 20))
+        + "-" + name;
+}
+
+
+Path makeOutputPath(const string & id,
+    const Hash & hash, const string & name)
+{
+    return makeStorePath("output:" + id, hash,
+        name + (id == "out" ? "" : "-" + id));
+}
+
+
+Path makeFixedOutputPath(bool recursive,
+    HashType hashAlgo, Hash hash, string name)
+{
+    return hashAlgo == htSHA256 && recursive
+        ? makeStorePath("source", hash, name)
+        : makeStorePath("output:out", hashString(htSHA256,
+                "fixed:out:" + (recursive ? (string) "r:" : "") +
+                printHashType(hashAlgo) + ":" + printHash(hash) + ":"),
+            name);
+}
+
+
+std::pair<Path, Hash> computeStorePathForPath(const Path & srcPath,
+    bool recursive, HashType hashAlgo, PathFilter & filter)
+{
+    HashType ht(hashAlgo);
+    Hash h = recursive ? hashPath(ht, srcPath, filter).first : hashFile(ht, srcPath);
+    string name = baseNameOf(srcPath);
+    Path dstPath = makeFixedOutputPath(recursive, hashAlgo, h, name);
+    return std::pair<Path, Hash>(dstPath, h);
+}
+
+
+Path computeStorePathForText(const string & name, const string & s,
+    const PathSet & references)
+{
+    Hash hash = hashString(htSHA256, s);
+    /* Stuff the references (if any) into the type.  This is a bit
+       hacky, but we can't put them in `s' since that would be
+       ambiguous. */
+    string type = "text";
+    foreach (PathSet::const_iterator, i, references) {
+        type += ":";
+        type += *i;
+    }
+    return makeStorePath(type, hash, name);
+}
+
+
+/* Return a string accepted by decodeValidPathInfo() that
+   registers the specified paths as valid.  Note: it's the
+   responsibility of the caller to provide a closure. */
+string StoreAPI::makeValidityRegistration(const PathSet & paths,
+    bool showDerivers, bool showHash)
+{
+    string s = "";
+    
+    foreach (PathSet::iterator, i, paths) {
+        s += *i + "\n";
+
+        ValidPathInfo info = queryPathInfo(*i);
+
+        if (showHash) {
+            s += printHash(info.hash) + "\n";
+            s += (format("%1%\n") % info.narSize).str();
+        }
+
+        Path deriver = showDerivers ? info.deriver : "";
+        s += deriver + "\n";
+
+        s += (format("%1%\n") % info.references.size()).str();
+
+        foreach (PathSet::iterator, j, info.references)
+            s += *j + "\n";
+    }
+
+    return s;
+}
+
+
+ValidPathInfo decodeValidPathInfo(std::istream & str, bool hashGiven)
+{
+    ValidPathInfo info;
+    getline(str, info.path);
+    if (str.eof()) { info.path = ""; return info; }
+    if (hashGiven) {
+        string s;
+        getline(str, s);
+        info.hash = parseHash(htSHA256, s);
+        getline(str, s);
+        if (!string2Int(s, info.narSize)) throw Error("number expected");
+    }
+    getline(str, info.deriver);
+    string s; int n;
+    getline(str, s);
+    if (!string2Int(s, n)) throw Error("number expected");
+    while (n--) {
+        getline(str, s);
+        info.references.insert(s);
+    }
+    if (!str || str.eof()) throw Error("missing input");
+    return info;
+}
+
+
+string showPaths(const PathSet & paths)
+{
+    string s;
+    foreach (PathSet::const_iterator, i, paths) {
+        if (s.size() != 0) s += ", ";
+        s += "`" + *i + "'";
+    }
+    return s;
+}
+
+
+void exportPaths(StoreAPI & store, const Paths & paths,
+    bool sign, Sink & sink)
+{
+    foreach (Paths::const_iterator, i, paths) {
+        writeInt(1, sink);
+        store.exportPath(*i, sign, sink);
+    }
+    writeInt(0, sink);
+}
+
+
+}
+
+
+#include "local-store.hh"
+#include "serialise.hh"
+#include "remote-store.hh"
+
+
+namespace nix {
+
+
+std::shared_ptr<StoreAPI> store;
+
+
+std::shared_ptr<StoreAPI> openStore(bool reserveSpace)
+{
+    if (getEnv("NIX_REMOTE") == "")
+        return std::shared_ptr<StoreAPI>(new LocalStore(reserveSpace));
+    else
+        return std::shared_ptr<StoreAPI>(new RemoteStore());
+}
+
+
+}