diff options
Diffstat (limited to 'src/nix.cc')
| -rw-r--r-- | src/nix.cc | 156 |
1 files changed, 2 insertions, 154 deletions
diff --git a/src/nix.cc b/src/nix.cc index 7990cde3af30..db9f187e20d8 100644 --- a/src/nix.cc +++ b/src/nix.cc @@ -11,155 +11,15 @@ #include <sys/types.h> #include <sys/wait.h> -extern "C" { -#include <aterm1.h> -} - #include "util.hh" #include "hash.hh" #include "db.hh" +#include "nix.hh" +#include "eval.hh" using namespace std; -/* Database names. */ - -/* dbRefs :: Hash -> FileName - - Maintains a mapping from hashes to filenames within the NixValues - directory. This mapping is for performance only; it can be - reconstructed unambiguously from the nixValues directory. The - reason is that names in this directory are not printed hashes but - also might carry some descriptive element (e.g., - "aterm-2.0-ae749a..."). Without this mapping, looking up a value - would take O(n) time because we would need to read the entire - directory. */ -static string dbRefs = "refs"; - -/* dbNFs :: Hash -> Hash - - Each pair (h1, h2) in this mapping records the fact that h2 is a - normal form obtained by evaluating the value h1. - - We would really like to have h2 be the hash of the object - referenced by h2. However, that gives a cyclic dependency: to - compute the hash (and thus the file name) of the object, we need to - compute the object, but to do that, we need the file name of the - object. - - So for now we abandon the requirement that - - hashFile(dbRefs[h]) == h. - - I.e., this property does not hold for computed normal forms. - Rather, we use h2 = hash(h1). This allows dbNFs to be - reconstructed. Perhaps using a pseudo random number would be - better to prevent the system from being subverted in some way. -*/ -static string dbNFs = "nfs"; - -/* dbNetSources :: Hash -> URL - - Each pair (hash, url) in this mapping states that the object - identified by hash can be obtained by fetching the object pointed - to by url. - - TODO: this should be Hash -> [URL] - - TODO: factor this out into a separate tool? */ -static string dbNetSources = "netsources"; - - -/* Path names. */ - -/* nixValues is the directory where all Nix values (both files and - directories, and both normal and non-normal forms) live. */ -static string nixValues; - -/* nixLogDir is the directory where we log evaluations. */ -static string nixLogDir; - -/* nixDB is the file name of the Berkeley DB database where we - maintain the dbXXX mappings. */ -static string nixDB; - - -/* Abstract syntax of Nix values: - - e := Hash(h) -- external reference - | Str(s) -- string constant - | Bool(b) -- boolean constant - | Name(e) -- "&" operator; pointer (file name) formation - | App(e, e) -- application - | Lam(x, e) -- lambda abstraction - | Exec(platform, e, e*) - -- primitive; execute e with args e* on platform - ; -*/ - - -/* Download object referenced by the given URL into the sources - directory. Return the file name it was downloaded to. */ -string fetchURL(string url) -{ - string filename = baseNameOf(url); - string fullname = nixSourcesDir + "/" + filename; - struct stat st; - if (stat(fullname.c_str(), &st)) { - cerr << "fetching " << url << endl; - /* !!! quoting */ - string shellCmd = - "cd " + nixSourcesDir + " && wget --quiet -N \"" + url + "\""; - int res = system(shellCmd.c_str()); - if (WEXITSTATUS(res) != 0) - throw Error("cannot fetch " + url); - } - return fullname; -} - - -/* Obtain an object with the given hash. If a file with that hash is - known to exist in the local file system (as indicated by the dbRefs - database), we use that. Otherwise, we attempt to fetch it from the - network (using dbNetSources). We verify that the file has the - right hash. */ -string getFile(Hash hash) -{ - bool checkedNet = false; - - while (1) { - - string fn, url; - - if (queryDB(nixDB, dbRefs, hash, fn)) { - - /* Verify that the file hasn't changed. !!! race */ - if (hashFile(fn) != hash) - throw Error("file " + fn + " is stale"); - - return fn; - } - - if (checkedNet) - throw Error("consistency problem: file fetched from " + url + - " should have hash " + (string) hash + ", but it doesn't"); - - if (!queryDB(nixDB, dbNetSources, hash, url)) - throw Error("a file with hash " + (string) hash + " is requested, " - "but it is not known to exist locally or on the network"); - - checkedNet = true; - - fn = fetchURL(url); - - setDB(nixDB, dbRefs, hash, fn); - } -} - - -typedef map<string, string> Params; - - void readPkgDescr(Hash hash, Params & pkgImports, Params & fileImports, Params & arguments) { @@ -204,9 +64,6 @@ void readPkgDescr(Hash hash, string getPkg(Hash hash); -typedef map<string, string> Environment; - - void fetchDeps(Hash hash, Environment & env) { /* Read the package description file. */ @@ -538,15 +395,6 @@ void registerInstalledPkg(Hash hash, string path) } -void initDB() -{ - createDB(nixDB, dbRefs); - createDB(nixDB, dbInstPkgs); - createDB(nixDB, dbPrebuilts); - createDB(nixDB, dbNetSources); -} - - void verifyDB() { /* Check that all file references are still valid. */ |