diff options
Diffstat (limited to 'src/values.cc')
-rw-r--r-- | src/values.cc | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/values.cc b/src/values.cc new file mode 100644 index 000000000000..064203ae2836 --- /dev/null +++ b/src/values.cc @@ -0,0 +1,100 @@ +#include "values.hh" +#include "globals.hh" +#include "db.hh" + + +static void copyFile(string src, string dst) +{ + int res = system(("cat " + src + " > " + dst).c_str()); /* !!! escape */ + if (WEXITSTATUS(res) != 0) + throw Error("cannot copy " + src + " to " + dst); +} + + +static string absValuePath(string s) +{ + return nixValues + "/" + s; +} + + +Hash addValue(string path) +{ + Hash hash = hashFile(path); + + string name; + if (queryDB(nixDB, dbRefs, hash, name)) { + debug((string) hash + " already known"); + return hash; + } + + string baseName = baseNameOf(path); + + string targetName = (string) hash + "-" + baseName; + + copyFile(path, absValuePath(targetName)); + + setDB(nixDB, dbRefs, hash, targetName); + + return hash; +} + + +#if 0 +/* 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; +} +#endif + + +string queryValuePath(Hash hash) +{ + bool checkedNet = false; + + while (1) { + + string name, url; + + if (queryDB(nixDB, dbRefs, hash, name)) { + string fn = absValuePath(name); + + /* Verify that the file hasn't changed. !!! race */ + if (hashFile(fn) != hash) + throw Error("file " + fn + " is stale"); + + return fn; + } + + throw Error("a file with hash " + (string) hash + " is requested, " + "but it is not known to exist locally or on the network"); +#if 0 + 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); +#endif + } +} |