TODO: templator for text backend

src/templates_text/templator_text.org

@@ -0,0 +1,858 @@
+#+Title: TEXT back end of the TREX Input/Ouput library (TREXIO)
+
+* File prefixes                                                     :noxport:
+
+  #+NAME:header
+  #+begin_src c 
+/* This file was generated from the trexio.org org-mode file.
+   To generate it, open trexio.org in Emacs and execute
+   M-x org-babel-tangle
+*/
+
+
+
+  #+end_src
+
+  #+begin_src c :tangle trexio_text.h :noweb yes
+<<header>>
+#ifndef _TREXIO_TEXT_H
+#define _TREXIO_TEXT_H
+
+#include "trexio.h"
+#include "trexio_s.h"
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+  #+end_src
+  
+  #+begin_src c :tangle trexio_text.c :noweb yes
+<<header>>
+#include "trexio_text.h"
+  #+end_src
+
+* TEXT Back end
+
+  The "file" produced by the text back end is a directory with one
+  file per group.
+  
+  When the file is open, it is locked by the current process. No other
+  process can read/write the same file. This guarantees that the
+  representation in memory is consistent with the file and avoid
+  re-reading the file before writing.
+  To lock the file, we lock the =.lock= file which is present in the
+  directory. 
+  
+  The file is written when closed, or when the flush function is called.
+  
+*** Structs for blocks
+    #+begin_src c :tangle trexio_text.h
+typedef struct nucleus_s {
+  FILE*    file;
+  uint64_t dim_coord;
+  uint64_t dim_charge;
+  double*  coord;
+  double*  charge;
+  uint64_t num;
+  int      to_flush;
+} nucleus_t;
+
+typedef struct electron_s {
+  FILE*    file;
+  uint64_t  alpha_num;
+  uint64_t  beta_num;
+  int       to_flush;
+} electron_t;
+
+typedef struct rdm_s {
+  FILE*    file;
+  uint64_t dim_one_e;
+  double*  one_e;
+  char*    two_e_file_name;
+  int      to_flush;
+} rdm_t;
+    #+end_src
+
+    
+*** TO DO
+    - to_flush = 1 in write
+    - to_flush = 0 when flushed
+    - name 
+
+*** Structs for the text back end
+    
+    #+begin_src c :tangle trexio_text.h
+typedef struct trexio_text_s {
+  trexio_t   parent ;
+  int        lock_file;
+
+  nucleus_t*  nucleus;
+  electron_t* electron;
+  rdm_t*      rdm;
+} trexio_text_t;
+
+    #+end_src
+
+*** Init/deinit functions
+
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_init(trexio_t* file);
+    #+end_src
+  
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_init(trexio_t* file) {
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+
+  trexio_text_t* f = (trexio_text_t*) file;
+
+ /* If directory doesn't exist, create it in write mode */
+  struct stat st;
+  
+  if (stat(file->file_name, &st) == 0 && S_ISDIR(st.st_mode)) {
+ /* Do nothing */
+  } else {
+    if (file->mode == 'r') return TREXIO_READONLY;
+    
+    if (mkdir(file->file_name, 0777) != 0) {
+      return TREXIO_FAILURE;
+    }
+  }  
+
+ /* Create the lock file in the directory */
+  const char* lock_file_name = "/.lock";
+  char* file_name = (char*)
+    calloc( strlen(file->file_name) + strlen(lock_file_name) + 1,
+            sizeof(char));
+  assert (file_name != NULL);
+  strcpy (file_name, file->file_name);
+  strcat (file_name, lock_file_name);
+
+  f->lock_file = open(file_name,O_WRONLY|O_CREAT|O_TRUNC, 0644);
+  assert (f->lock_file > 0);
+  free(file_name);
+
+  f->nucleus = NULL;
+  f->electron= NULL;
+  f->rdm     = NULL;
+  
+  return TREXIO_SUCCESS;
+}
+
+    #+end_src
+
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_lock(trexio_t* file);
+    #+end_src
+  
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_lock(trexio_t* file) {
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+
+  trexio_text_t* f = (trexio_text_t*) file;
+
+  struct flock fl;
+  
+  fl.l_type   = F_WRLCK;
+  fl.l_whence = SEEK_SET;
+  fl.l_start  = 0;       
+  fl.l_len    = 0;       
+  fl.l_pid    = getpid();
+  
+  int rc = fcntl(f->lock_file, F_SETLKW, &fl);
+  if (rc == -1) return TREXIO_FAILURE;
+
+  return TREXIO_SUCCESS;
+}
+
+    #+end_src
+
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_finalize(trexio_t* file);
+    #+end_src
+    
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_finalize(trexio_t* file) {
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+
+  trexio_exit_code rc;
+  rc = trexio_text_free_nucleus( (trexio_text_t*) file);
+  assert (rc == TREXIO_SUCCESS);
+
+  rc = trexio_text_free_rdm( (trexio_text_t*) file);
+  assert (rc == TREXIO_SUCCESS);
+  
+  return TREXIO_SUCCESS;
+}
+    #+end_src
+
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_unlock(trexio_t* file);
+    #+end_src
+    
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_unlock(trexio_t* file) {
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+
+  trexio_text_t* f = (trexio_text_t*) file;
+
+  struct flock fl;
+
+  fl.l_type   = F_WRLCK;
+  fl.l_whence = SEEK_SET;
+  fl.l_start  = 0;         
+  fl.l_len    = 0;         
+  fl.l_pid    = getpid();  
+  fl.l_type   = F_UNLCK;   
+  fcntl(f->lock_file, F_SETLK, &fl);
+    
+  close(f->lock_file);
+  return TREXIO_SUCCESS;
+}
+    #+end_src
+
+*** Nucleus struct
+
+**** Read the struct
+
+    #+begin_src c :tangle trexio_text.h
+nucleus_t* trexio_text_read_nucleus(trexio_text_t* file);
+    #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+nucleus_t* trexio_text_read_nucleus(trexio_text_t* file) {
+  if (file == NULL) return NULL;
+
+  if (file->nucleus != NULL) return file->nucleus;
+  
+ /* Allocate the data structure */
+  nucleus_t* nucleus = (nucleus_t*) malloc(sizeof(nucleus_t));
+  assert (nucleus != NULL);
+
+  nucleus->file     = NULL;
+  nucleus->num      = 0;
+  nucleus->coord    = NULL;
+  nucleus->charge   = NULL;
+  nucleus->to_flush = 0;
+
+ /* Try to open the file. If the file does not exist, return */
+  const char* nucleus_file_name = "/nucleus.txt";
+  char * file_name = (char*)
+    calloc( strlen(file->parent.file_name) + strlen(nucleus_file_name) + 1,
+            sizeof(char));
+  assert (file_name != NULL);
+  strcpy (file_name, file->parent.file_name);
+  strcat (file_name, nucleus_file_name);
+
+ /* If the file exists, read it */
+  FILE* f = fopen(file_name,"r");
+  if (f != NULL) {
+    
+ /* Find size of file to allocate the max size of the string buffer */
+    fseek(f, 0L, SEEK_END);
+    size_t sz = ftell(f);
+    fseek(f, 0L, SEEK_SET);
+    char* buffer = (char*) malloc(sz*sizeof(char));
+    
+ /* Read the dimensioning variables */
+    int rc;
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "dim_charge") == 0);
+    
+    rc = fscanf(f, "%lu", &(nucleus->dim_charge));
+    assert (rc == 1);
+    
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "dim_coord") == 0);
+    
+    rc = fscanf(f, "%lu", &(nucleus->dim_coord));
+    assert (rc == 1);
+    
+ /* Allocate arrays */
+    nucleus->charge = (double*) calloc(nucleus->dim_charge, sizeof(double));
+    assert (nucleus->charge != NULL);
+    
+    nucleus->coord = (double*) calloc(nucleus->dim_coord, sizeof(double));
+    assert (nucleus->coord != NULL);
+    
+ /* Read data */
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "num") == 0);
+    
+    rc = fscanf(f, "%lu", &(nucleus->num));
+    assert (rc == 1);
+    
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "charge") == 0);
+    
+    for (uint64_t i=0 ; i<nucleus->dim_charge ; i++) {
+      rc = fscanf(f, "%lf", &(nucleus->charge[i]));
+      assert (rc == 1);
+    }
+    
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "coord") == 0);
+    
+    for (uint64_t i=0 ; i<nucleus->dim_coord ; i++) {
+      rc = fscanf(f, "%lf", &(nucleus->coord[i]));
+      assert (rc == 1);
+    }
+    free(buffer);
+    fclose(f);
+    f = NULL;
+  }
+  if (file->parent.mode == 'w') {
+    nucleus->file = fopen(file_name,"a");  
+  } else { 
+    nucleus->file = fopen(file_name,"r");  
+  }
+  free(file_name);
+  file->nucleus = nucleus;
+  return nucleus;
+}
+   #+end_src
+
+**** Flush the struct
+
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_flush_nucleus(const trexio_text_t* file);
+    #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_flush_nucleus(const trexio_text_t* file) {
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+
+  if (file->parent.mode == 'r') return TREXIO_READONLY;
+
+  nucleus_t* nucleus = file->nucleus;
+  
+  if (nucleus == NULL) return TREXIO_SUCCESS;
+
+  if (nucleus->to_flush == 0) return TREXIO_SUCCESS;
+
+  FILE* f = nucleus->file;
+  assert (f != NULL);
+  rewind(f);
+
+ /* Write the dimensioning variables */
+  fprintf(f, "dim_charge %ld\n", nucleus->dim_charge);
+  fprintf(f, "dim_coord  %ld\n", nucleus->dim_coord );
+
+ /* Write arrays */
+  fprintf(f, "num %ld\n", nucleus->num);
+  fprintf(f, "charge\n");
+  for (uint64_t i=0 ; i<nucleus->dim_charge ; i++) {
+    fprintf(f, "%lf\n", nucleus->charge[i]);
+  }
+
+  fprintf(f, "coord\n");
+  for (uint64_t i=0 ; i<nucleus->dim_coord ; i++) {
+      fprintf(f, "%lf\n", nucleus->coord[i]);
+  }
+  fflush(f);
+  file->nucleus->to_flush = 0;
+  return TREXIO_SUCCESS;
+}
+   #+end_src
+
+**** Free memory
+
+     Memory is allocated when reading. The following function frees memory.
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_free_nucleus(trexio_text_t* file);
+    #+end_src
+    
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_free_nucleus(trexio_text_t* file) {
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+  
+  trexio_exit_code rc;
+
+  if (file->parent.mode != 'r') {
+    rc = trexio_text_flush_nucleus(file);
+    if (rc != TREXIO_SUCCESS) return TREXIO_FAILURE;
+  }
+
+  nucleus_t* nucleus = file->nucleus;
+  if (nucleus == NULL) return TREXIO_SUCCESS;
+
+  if (nucleus->file != NULL) {
+    fclose(nucleus->file);
+    nucleus->file = NULL;
+  }
+
+  if (nucleus->coord != NULL) {
+    free (nucleus->coord);
+    nucleus->coord = NULL;
+  }
+  
+  if (nucleus->charge != NULL) {
+    free (nucleus->charge);
+    nucleus->charge = NULL;
+  }
+  
+  free (nucleus);
+  file->nucleus = NULL;
+  return TREXIO_SUCCESS;
+}
+    #+end_src
+
+**** Read/Write the num attribute
+
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_read_nucleus_num(const trexio_t* file, uint64_t* num);
+trexio_exit_code trexio_text_write_nucleus_num(const trexio_t* file, const uint64_t num);
+   #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_read_nucleus_num(const trexio_t* file, uint64_t* num) {
+
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+  if (num   == NULL) return TREXIO_INVALID_ARG_2;
+
+  nucleus_t* nucleus = trexio_text_read_nucleus((trexio_text_t*) file);
+  if (nucleus == NULL) return TREXIO_FAILURE;
+
+ /**/ *num = nucleus->num;
+
+  return TREXIO_SUCCESS;
+}
+
+ 
+trexio_exit_code trexio_text_write_nucleus_num(const trexio_t* file, const uint64_t num) {
+
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+
+  if (file->mode == 'r') return TREXIO_READONLY;
+  
+  nucleus_t* nucleus = trexio_text_read_nucleus((trexio_text_t*) file);
+  if (nucleus == NULL) return TREXIO_FAILURE;
+  
+  nucleus->num = num;
+  nucleus->to_flush = 1;
+  
+  return TREXIO_SUCCESS;
+}
+     #+end_src
+
+**** Read/Write the coord attribute
+
+     The ~coord~ array is assumed allocated with the appropriate size.
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_read_nucleus_coord(const trexio_t* file, double* coord, const uint64_t dim_coord);
+trexio_exit_code trexio_text_write_nucleus_coord(const trexio_t* file, const double* coord, const uint64_t dim_coord);
+   #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_read_nucleus_coord(const trexio_t* file, double* coord, const uint64_t dim_coord) {
+
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+  if (coord == NULL) return TREXIO_INVALID_ARG_2;
+
+  nucleus_t* nucleus = trexio_text_read_nucleus((trexio_text_t*) file);
+  if (nucleus == NULL) return TREXIO_FAILURE;
+
+  if (dim_coord != nucleus->dim_coord) return TREXIO_INVALID_ARG_3;
+  
+  for (uint64_t i=0 ; i<dim_coord ; i++) {
+    coord[i] = nucleus->coord[i];
+  }
+
+  return TREXIO_SUCCESS;
+}
+
+ 
+trexio_exit_code trexio_text_write_nucleus_coord(const trexio_t* file, const double* coord, const uint64_t dim_coord) {
+  if (file  == NULL)  return TREXIO_INVALID_ARG_1;
+  if (coord == NULL)  return TREXIO_INVALID_ARG_2;
+
+  if (file->mode == 'r') return TREXIO_READONLY;
+
+  nucleus_t* nucleus = trexio_text_read_nucleus((trexio_text_t*) file);
+  if (nucleus == NULL) return TREXIO_FAILURE;
+  
+  if (nucleus->coord != NULL) {
+    free(nucleus->coord);
+    nucleus->coord = NULL;
+  }
+
+  nucleus->dim_coord = dim_coord;
+  nucleus->coord = (double*) calloc(dim_coord, sizeof(double));
+
+  for (uint64_t i=0 ; i<dim_coord ; i++) {
+    nucleus->coord[i] = coord[i];
+  }
+  
+  nucleus->to_flush = 1;
+  return TREXIO_SUCCESS;
+}
+     #+end_src
+**** Read/Write the charge attribute
+
+     The ~charge~ array is assumed allocated with the appropriate size.
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_read_nucleus_charge(const trexio_t* file, double* charge, const uint64_t dim_charge);
+trexio_exit_code trexio_text_write_nucleus_charge(const trexio_t* file, const double* charge, const uint64_t dim_charge);
+   #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_read_nucleus_charge(const trexio_t* file, double* charge, const uint64_t dim_charge) {
+
+  if (file   == NULL) return TREXIO_INVALID_ARG_1;
+  if (charge == NULL) return TREXIO_INVALID_ARG_2;
+
+  nucleus_t* nucleus = trexio_text_read_nucleus((trexio_text_t*) file);
+  if (nucleus == NULL) return TREXIO_FAILURE;
+
+  if (dim_charge != nucleus->dim_charge) return TREXIO_INVALID_ARG_3;
+  
+  for (uint64_t i=0 ; i<dim_charge ; i++) {
+    charge[i] = nucleus->charge[i];
+  }
+
+  return TREXIO_SUCCESS;
+}
+
+ 
+trexio_exit_code trexio_text_write_nucleus_charge(const trexio_t* file, const double* charge, const uint64_t dim_charge) {
+  if (file   == NULL)  return TREXIO_INVALID_ARG_1;
+  if (charge == NULL)  return TREXIO_INVALID_ARG_2;
+
+  if (file->mode == 'r') return TREXIO_READONLY;
+
+  nucleus_t* nucleus = trexio_text_read_nucleus((trexio_text_t*) file);
+  if (nucleus == NULL) return TREXIO_FAILURE;
+  
+  if (nucleus->charge != NULL) {
+    free(nucleus->charge);
+    nucleus->charge = NULL;
+  }
+
+  nucleus->dim_charge = dim_charge;
+  nucleus->charge = (double*) calloc(dim_charge, sizeof(double));
+
+  for (uint64_t i=0 ; i<dim_charge ; i++) {
+    nucleus->charge[i] = charge[i];
+  }
+  
+  nucleus->to_flush = 1;
+  return TREXIO_SUCCESS;
+}
+     #+end_src
+
+*** RDM struct
+**** Read the complete struct
+
+    #+begin_src c :tangle trexio_text.h
+rdm_t* trexio_text_read_rdm(trexio_text_t* file);
+    #+end_src
+    
+    #+begin_src c :tangle trexio_text.c
+rdm_t* trexio_text_read_rdm(trexio_text_t* file) {
+  if (file  == NULL) return NULL;
+
+  if (file->rdm != NULL) return file->rdm;
+
+ /* Allocate the data structure */
+  rdm_t* rdm = (rdm_t*) malloc(sizeof(rdm_t));
+  assert (rdm != NULL);
+
+  rdm->one_e           = NULL;
+  rdm->two_e_file_name = NULL;
+  rdm->file            = NULL;
+  rdm->to_flush        = 0;
+
+ /* Try to open the file. If the file does not exist, return */
+  const char* rdm_file_name = "/rdm.txt";
+  char * file_name = (char*)
+    calloc( strlen(file->parent.file_name) + strlen(rdm_file_name) + 1,
+            sizeof(char));
+  assert (file_name != NULL);
+  strcpy (file_name, file->parent.file_name);
+  strcat (file_name, rdm_file_name);
+
+ /* If the file exists, read it */
+  FILE* f = fopen(file_name,"r");
+  if (f != NULL) {
+    
+ /* Find size of file to allocate the max size of the string buffer */
+    fseek(f, 0L, SEEK_END);
+    size_t sz = ftell(f);
+    fseek(f, 0L, SEEK_SET);
+    char* buffer = (char*) malloc(sz*sizeof(char));
+    
+ /* Read the dimensioning variables */
+    int rc;
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "dim_one_e") == 0);
+    
+    rc = fscanf(f, "%lu", &(rdm->dim_one_e));
+    assert (rc == 1);
+    
+ /* Allocate arrays */
+    rdm->one_e = (double*) calloc(rdm->dim_one_e, sizeof(double));
+    assert (rdm->one_e != NULL);
+    
+ /* Read one_e */
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "one_e") == 0);
+    
+    for (uint64_t i=0 ; i<rdm->dim_one_e; i++) {
+      rc = fscanf(f, "%lf", &(rdm->one_e[i]));
+      assert (rc == 1);
+    }
+    
+ /* Read two_e */
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    assert (strcmp(buffer, "two_e_file_name") == 0);
+    
+    rc = fscanf(f, "%s", buffer);
+    assert (rc == 1);
+    rdm->two_e_file_name = (char*) malloc (strlen(buffer)*sizeof(char));
+    strcpy(rdm->two_e_file_name, buffer);
+    
+    free(buffer);
+    fclose(f);
+    f = NULL;
+  }
+  if (file->parent.mode == 'w') {
+    rdm->file = fopen(file_name,"a");  
+  } else {
+    rdm->file = fopen(file_name,"r");  
+  }
+  free(file_name);
+  file->rdm = rdm ;
+  return rdm;
+}
+   #+end_src
+
+**** Flush the complete struct
+
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_flush_rdm(const trexio_text_t* file);
+    #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_flush_rdm(const trexio_text_t* file) {
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+
+  if (file->parent.mode == 'r') return TREXIO_READONLY;
+
+  rdm_t* rdm = file->rdm;
+  if (rdm == NULL) return TREXIO_SUCCESS;
+
+  if (rdm->to_flush == 0) return TREXIO_SUCCESS;
+
+  FILE* f = rdm->file;
+  assert (f != NULL);
+  rewind(f);
+
+ /* Write the dimensioning variables */
+  fprintf(f, "num %ld\n", rdm->dim_one_e);
+
+ /* Write arrays */
+  fprintf(f, "one_e\n");
+  for (uint64_t i=0 ; i< rdm->dim_one_e; i++) {
+    fprintf(f, "%lf\n", rdm->one_e[i]);
+  }
+
+  fprintf(f, "two_e_file_name\n");
+  fprintf(f, "%s\n", rdm->two_e_file_name);
+
+  fflush(f);
+  file->rdm->to_flush = 0;
+  return TREXIO_SUCCESS;
+}
+   #+end_src
+
+**** Free memory
+
+     Memory is allocated when reading. The followig function frees memory.
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_free_rdm(trexio_text_t* file);
+    #+end_src
+    
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_free_rdm(trexio_text_t* file) {
+  if (file == NULL) return TREXIO_INVALID_ARG_1;
+  
+  trexio_exit_code rc;
+  if (file->parent.mode != 'r') {
+    rc = trexio_text_flush_rdm(file);
+    if (rc != TREXIO_SUCCESS) return TREXIO_FAILURE;
+  }
+
+  rdm_t* rdm = file->rdm;
+  if (rdm == NULL) return TREXIO_SUCCESS;
+
+  if (rdm->file != NULL) {
+    fclose(rdm->file);
+    rdm->file = NULL;
+  }
+  
+  if (rdm->one_e != NULL) {
+    free (rdm->one_e);
+    rdm->one_e = NULL;
+  }
+  
+  if (rdm->two_e_file_name != NULL) {
+    free (rdm->two_e_file_name);
+    rdm->two_e_file_name = NULL;
+  }
+  
+  free (rdm);
+  file->rdm = NULL;
+  return TREXIO_SUCCESS;
+}
+    #+end_src
+
+**** Read/Write the one_e attribute
+
+     The ~one_e~ array is assumed allocated with the appropriate size.
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_read_rdm_one_e(const trexio_t* file, double* one_e, const uint64_t dim_one_e);
+trexio_exit_code trexio_text_write_rdm_one_e(const trexio_t* file, const double* one_e, const uint64_t dim_one_e);
+   #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_read_rdm_one_e(const trexio_t* file, double* one_e, const uint64_t dim_one_e) {
+
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+  if (one_e == NULL) return TREXIO_INVALID_ARG_2;
+
+  rdm_t* rdm = trexio_text_read_rdm((trexio_text_t*) file);
+  if (rdm == NULL) return TREXIO_FAILURE;
+
+  if (dim_one_e != rdm->dim_one_e) return TREXIO_INVALID_ARG_3;
+
+  for (uint64_t i=0 ; i<dim_one_e ; i++) {
+    one_e[i] = rdm->one_e[i];
+  }
+
+  return TREXIO_SUCCESS;
+}
+
+ 
+trexio_exit_code trexio_text_write_rdm_one_e(const trexio_t* file, const double* one_e, const uint64_t dim_one_e) {
+  if (file  == NULL)  return TREXIO_INVALID_ARG_1;
+  if (one_e == NULL)  return TREXIO_INVALID_ARG_2;
+  if (file->mode != 'r') return TREXIO_READONLY;
+
+  rdm_t* rdm = trexio_text_read_rdm((trexio_text_t*) file);
+  if (rdm == NULL) return TREXIO_FAILURE;
+  
+  rdm->dim_one_e = dim_one_e;
+  for (uint64_t i=0 ; i<dim_one_e ; i++) {
+    rdm->one_e[i] = one_e[i];
+  }
+  
+  rdm->to_flush = 1;
+  return TREXIO_SUCCESS;
+}
+     #+end_src
+
+**** Read/Write the two_e attribute
+
+ ~two_e~ is a sparse data structure, which can be too large to fit
+     in memory. So we provide functions to read and write it by
+     chunks.
+     In the text back end, the easiest way to do it is to create a
+     file for each sparse float structure.
+    
+    #+begin_src c :tangle trexio_text.h
+trexio_exit_code trexio_text_buffered_read_rdm_two_e(const trexio_t* file, const uint64_t offset, const uint64_t size, int64_t* index, double* value);
+trexio_exit_code trexio_text_buffered_write_rdm_two_e(const trexio_t* file, const uint64_t offset, const uint64_t size, const int64_t* index, const double* value);
+   #+end_src
+
+    #+begin_src c :tangle trexio_text.c
+trexio_exit_code trexio_text_buffered_read_rdm_two_e(const trexio_t* file, const uint64_t offset, const uint64_t size, int64_t* index, double* value) {
+
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+  if (index == NULL) return TREXIO_INVALID_ARG_4;
+  if (value == NULL) return TREXIO_INVALID_ARG_5;
+
+  rdm_t* rdm = trexio_text_read_rdm((trexio_text_t*) file);
+  if (rdm == NULL) return TREXIO_FAILURE;
+
+  FILE* f = fopen(rdm->two_e_file_name, "r");
+  if (f == NULL) return TREXIO_END;
+
+  const uint64_t line_length = 64;
+  fseek(f, (long) offset * line_length, SEEK_SET);
+  
+  int rc;
+  for (uint64_t i=0 ; i<size ; i++) {
+    rc = fscanf(f, "%9ld %9ld %9ld %9ld %24le\n",
+           &index[4*i], 
+           &index[4*i+1], 
+           &index[4*i+2], 
+           &index[4*i+3], 
+           &value[i]);
+    if (rc == 5) {
+ /* Do nothing */
+    } else if (rc == EOF) {
+      return TREXIO_END;
+    } else if (rc == EOF) {
+      return TREXIO_FAILURE;
+    }
+  }
+
+  return TREXIO_SUCCESS;
+}
+
+ 
+trexio_exit_code trexio_text_buffered_write_rdm_two_e(const trexio_t* file, const uint64_t offset, const uint64_t size, const int64_t* index, const double* value) {
+  if (file  == NULL) return TREXIO_INVALID_ARG_1;
+  if (index == NULL) return TREXIO_INVALID_ARG_4;
+  if (value == NULL) return TREXIO_INVALID_ARG_5;
+  if (file->mode != 'r') return TREXIO_READONLY;
+
+  rdm_t* rdm = trexio_text_read_rdm((trexio_text_t*) file);
+  if (rdm == NULL) return TREXIO_FAILURE;
+
+  FILE* f = fopen(rdm->two_e_file_name, "w");
+  if (f == NULL) return TREXIO_FAILURE;
+
+  const uint64_t line_length = 64;
+  fseek(f, (long) offset * line_length, SEEK_SET);
+  
+  int rc;
+  for (uint64_t i=0 ; i<size ; i++) {
+    rc = fprintf(f, "%9ld %9ld %9ld %9ld %24le\n",
+           index[4*i], 
+           index[4*i+1], 
+           index[4*i+2], 
+           index[4*i+3], 
+           value[i]);
+    if (rc != 5) return TREXIO_FAILURE;
+  }
+
+  return TREXIO_SUCCESS;
+}
+     #+end_src
+
+* File suffixes                                                     :noxport:
+
+  #+begin_src c :tangle trexio_text.h
+#endif
+  #+end_src
+