1 files changed, 278 insertions, 0 deletions

diff --git a/lib/sitecing_util.cc b/lib/sitecing_util.cc
new file mode 100644
index 0000000..9b6c54e
--- a/dev/null
+++ b/lib/sitecing_util.cc
@@ -0,0 +1,278 @@
+#ifdef USE_PCH
+ #include "pch.h"
+#else
+ #include <sys/stat.h>
+ #include <sys/types.h>
+ #include <unistd.h>
+ #include <fcntl.h>
+ #include <sys/ipc.h>
+ #include <sys/sem.h>
+ #include <errno.h>
+ #include <iostream>
+ #include <fstream>
+ #include <cassert>
+ #include "sitecing/sitecing_util.h"
+#endif
+
+namespace sitecing {
+
+    /*
+     * XXX: all of these utilities could be sheerly optimized.
+     */
+
+    string normalize_path(const string& path,int opts) {
+        const char *s = path.c_str();
+        string rv;
+        string::size_type notslash = 0;
+        if( (*s)=='.' && s[1]=='/' )
+            s+=2;
+        if(opts&strip_leading_slash)
+            for(;(*s) && (*s)=='/';s++);
+        for(;*s;s++) {
+            if( (*s)=='/' ) {
+                if(s[1]=='/')
+                    continue;
+                if(s[1]=='.' && s[2]=='/') {
+                    s+=2;
+                    continue;
+                }
+            }
+            if(opts&restrict_dotdot) {
+                if(
+                                ( rv.empty() && s[0]=='.' && s[1]=='.' && s[2]=='/' )// "^../"
+                        || ( s[0]=='/' && s[1]=='.' && s[2]=='.' && (s[3]==0 || s[3]=='/') ) // "/..(/|$)"
+                  )
+                    throw utility_restricted_sequence(CODEPOINT,"restricted updir sequence encountered");
+            }
+            rv += *s;
+            if( (*s) != '/' )
+                notslash=rv.length();
+        }
+        if(!(opts&strip_trailing_slash))
+            notslash++;
+        if(notslash<rv.length())
+            rv.erase(notslash); // XXX: check the logic of stripping/not strippling trailing slash
+        return rv;
+    }
+
+    string strip_prefix(const string& str,const string& prefix) {
+        if(str.compare(0,prefix.length(),prefix))
+            throw utility_no_prefix(CODEPOINT,"no such prefix");
+        return str.substr(prefix.length());
+    }
+
+    string strip_suffix(const string& str,const string& suffix) {
+        if(str.compare(str.length()-suffix.length(),suffix.length(),suffix))
+            throw utility_no_suffix(CODEPOINT,"no such suffix");
+        return str.substr(0,str.length()-suffix.length());
+    }
+
+    string dir_name(const string& filename) {
+        string::size_type sl = filename.find_last_of('/');
+        if(sl==string::npos)
+            return ""; // no slashes -- no dir.
+        string::size_type nosl = filename.find_last_not_of('/',sl);
+        if(nosl==string::npos)
+            return ""; // only slashes -- no dir. XXX: only slashes after the last slash... does it mean no dir?
+        return filename.substr(0,nosl+1);
+    }
+
+    void make_path(const string& path,mode_t mode) {
+        struct stat st;
+        for(string::size_type sl=0;sl!=string::npos;sl=path.find('/',sl+1)) {
+            if(!sl)
+                continue;
+            string p = path.substr(0,sl);
+            if(stat(p.c_str(),&st) || !S_ISDIR(st.st_mode)) {
+                if(mkdir(p.c_str(),mode))
+                    throw konforka::exception(CODEPOINT,"failed to mkdir()");
+            }
+        }
+        if(stat(path.c_str(),&st) || !S_ISDIR(st.st_mode)) {
+            if(mkdir(path.c_str(),mode))
+                throw konforka::exception(CODEPOINT,"failed to mkdir()");
+        }
+    }
+
+    void file_lock::lock(const string& f) {
+        unlock();
+        fd = open(f.c_str(),O_CREAT|O_RDWR,S_IRUSR|S_IWUSR);
+        if(fd<0)
+            throw konforka::exception(CODEPOINT,"failed to open/create lockfile");
+        try {
+            lock();
+        }catch(konforka::exception& ke) {
+            ke.see(CODEPOINT);
+            close(fd); fd=-1;
+            throw;
+        }catch(...) {
+            close(fd); fd=-1;
+            throw;
+        }
+    }
+    void file_lock::lock() {
+        assert(fd>=0);
+        struct flock fl;
+        fl.l_type = F_WRLCK;
+        fl.l_whence=SEEK_SET;
+        fl.l_start=fl.l_len=0;
+        for(int tries=3;tries;tries--) {
+            if(!fcntl(fd,F_SETLK,&fl))
+                return;
+            sleep(8);
+        }
+        throw konforka::exception(CODEPOINT,"failed to obtain file lock");
+    }
+    void file_lock::unlock() {
+        if(fd<0)
+            return;
+        struct flock fl;
+        fl.l_type = F_UNLCK;
+        fl.l_whence=SEEK_SET;
+        fl.l_start=fl.l_len=0;
+        int rv = fcntl(fd,F_SETLK,&fl);
+        close(fd);
+        fd=-1;
+        if(rv)
+            throw konforka::exception(CODEPOINT,"failed to release file lock");
+    }
+
+    void pid_file::set(const string& f,bool u) {
+        ofstream of(f.c_str(),ios::trunc);
+        if(!of)
+            throw konforka::exception(CODEPOINT,"failed to open file for writing pid");
+        of << getpid() << endl;
+        of.close();
+        file_name = f;
+        unlink_pid = u;
+    }
+    void pid_file::unlink() {
+        if(!unlink_pid)
+            return;
+        ::unlink(file_name.c_str());
+    }
+
+    void semaphore::init() {
+        deinit();
+        semid = semget(IPC_PRIVATE,1,IPC_CREAT|0600);
+        if(semid<0)
+            throw konforka::exception(CODEPOINT,"failed to semget()");
+        if(semctl(semid,0,SETVAL,1))
+            throw konforka::exception(CODEPOINT,"failed to semctl()");
+    }
+    void semaphore::deinit() {
+        if(semid<0)
+            return;
+        semctl(semid,0,IPC_RMID,0);
+    }
+    void semaphore::on() {
+        assert(semid>=0);
+        struct sembuf sb;
+        sb.sem_num=0;
+        sb.sem_op=-1;
+        sb.sem_flg = SEM_UNDO;
+        while(semop(semid,&sb,1)<0) {
+            if(errno!=EINTR)
+                throw konforka::exception(CODEPOINT,"failed to semop()");
+        }
+    }
+    void semaphore::off() {
+        assert(semid>=0);
+        struct sembuf sb;
+        sb.sem_num=0;
+        sb.sem_op=1;
+        sb.sem_flg = SEM_UNDO;
+        while(semop(semid,&sb,1)<0) {
+            if(errno!=EINTR)
+                throw konforka::exception(CODEPOINT,"failed to semop()");
+        }
+    }
+
+    void semaphore_lock::lock() {
+        assert(sem);
+        if(locked)
+            return;
+        sem->on();
+        locked = true;
+    }
+    void semaphore_lock::unlock() {
+        if(!sem)
+            return;
+        if(!locked)
+            return;
+        sem->off();
+        locked=false;
+    }
+
+    string combine_path(const string& origin,const string& relative,int opts) {
+        string r = normalize_path(relative,0);
+        string rv;
+        // XXX: what to do if relative is empty is a question, really.
+        if(r.empty()) {
+            return normalize_path( (opts&origin_is_file)?dir_name(origin):origin ,strip_leading_slash|restrict_dotdot|strip_trailing_slash);
+        }else{
+            if(r[0]=='/') {
+                r.erase(0,1);
+            }else{
+                rv = normalize_path((opts&origin_is_file)?dir_name(origin):origin,restrict_dotdot|strip_trailing_slash);
+            }
+        }
+        string::size_type lsl = rv.rfind('/');
+        for(string::size_type sl=r.find('/');sl!=string::npos;sl=r.find('/')) {
+            assert(sl!=0);
+            if(sl==1 && r[0]=='.') {
+                // it's a "./"
+                r.erase(0,2);
+            }else if(sl==2 && r[0]=='.' && r[1]=='.') {
+                // we have a "../"
+                if(lsl==string::npos) {
+                    if(rv.empty() && (opts&fail_beyond_root))
+                        throw utility_beyond_root(CODEPOINT,"went beyond root while combining path");
+                    rv.clear();
+                }else{
+                    rv.erase(lsl);
+                    lsl = rv.rfind('/');
+                }
+                r.erase(0,3);
+            }else{
+                // we have a "something/"
+                lsl = rv.length();
+                rv += '/';
+                rv += r.substr(0,sl);
+                r.erase(0,sl+1);
+            }
+        }
+        if(r.empty())
+            return rv+'/';
+        if(r.length()==2 && r[0]=='.' && r[0]=='.') {
+            if(lsl==string::npos) {
+                if(rv.empty() & (opts&fail_beyond_root))
+                    throw utility_beyond_root(CODEPOINT,"went beyond root while combining path");
+                return "/";
+            }else{
+                rv.erase(lsl+1);
+                return rv;
+            }
+        }
+        rv += '/';
+        rv += r;
+        return rv;
+    }
+
+    void auto_chdir::pushdir(const string& td,bool ap) {
+        char *tmp = get_current_dir_name();
+        assert(tmp);
+        saved_pwd = tmp;
+        free(tmp);
+        autopop=ap;
+        if(chdir(td.c_str()))
+            throw konforka::exception(CODEPOINT,"failed to chdir()");
+    }
+    void auto_chdir::popdir() {
+        autopop=false;
+        if(chdir(saved_pwd.c_str()))
+            throw konforka::exception(CODEPOINT,"failed to chdir()");
+        // XXX: or should it be thrown? after all we call it from destructor...
+    }
+
+}