Add custom previews support

config.c

@@ -0,0 +1,208 @@
+#include "lexer.h"
+#include "error.h"
+#include "preview.h"
+
+#define CHECK(f, cond) \
+    do {               \
+        int x = (f);   \
+        if (cond)      \
+            return x;  \
+    } while (0)
+
+#define CHECK_OK(f)      CHECK(f, x != STAT_OK)
+#define CHECK_NULL(f)    CHECK(f, x != STAT_NULL)
+#define CHECK_OK_NULL(f) CHECK(f, x != STAT_OK || x != STAT_NULL)
+
+enum {
+    STAT_OK,
+    STAT_ERR,
+    STAT_NULL,
+};
+
+static Lexer *lexer;
+static Token token;
+static VectorPreview *previews;
+static char *any_type;
+
+static void add_preview(char *name, char *script, char *type, char *subtype,
+                       char *ext)
+{
+    if (type && strcmp(type, any_type) == 0)
+        type = NULL;
+
+    if (subtype && strcmp(subtype, any_type) == 0)
+        subtype = NULL;
+
+    Preview p = (Preview){
+        .name = name,
+        .script = script,
+        .script_len = strlen(script),
+        .type = type,
+        .subtype = subtype,
+        .ext = ext,
+        .priority = 1 /* custom previews are always prioritized */
+    };
+
+    vectorPreview_append(previews, p);
+}
+
+static inline void next_token(void)
+{
+    token = lexer_get_token(lexer);
+}
+
+static int accept(enum TokenType type)
+{
+    if (token.type == type) {
+        next_token();
+        return STAT_OK;
+    }
+
+    return STAT_NULL;
+}
+
+static int expect(enum TokenType type)
+{
+    if (accept(type) == STAT_OK)
+        return STAT_OK;
+
+    if (token.type == TOK_ERR)
+        return STAT_ERR;
+
+    print_errorf("unexpected token: %s, expected: %s",
+                 lexer_token_type_str(token.type),
+                 lexer_token_type_str(type));
+    return STAT_ERR;
+}
+
+static inline char *get_str(Token tok)
+{
+    return lexer_get_string(lexer, tok);
+}
+
+static int preview_type_ext(char **ext)
+{
+    CHECK_OK(accept(TOK_DOT));
+
+    Token tok = token;
+    CHECK_OK(expect(TOK_STR));
+    *ext = get_str(tok);
+
+    return STAT_OK;
+}
+
+static int preview_type_mime_part(char **s)
+{
+    *s = NULL;
+    CHECK_NULL(accept(TOK_STAR));
+
+    Token t = token;
+    CHECK_OK(expect(TOK_STR));
+    *s = get_str(t);
+
+    return STAT_OK;
+}
+
+static int preview_type_mime(char **type, char **subtype)
+{
+    CHECK_OK(preview_type_mime_part(type));
+    CHECK_OK(expect(TOK_SLASH));
+    CHECK_OK(preview_type_mime_part(subtype));
+
+    return STAT_OK;
+}
+
+static int preview_type(char **type, char **subtype, char **ext)
+{
+    CHECK_NULL(preview_type_ext(ext));
+    return preview_type_mime(type, subtype);
+}
+
+static int new_preview(void)
+{
+    Token name = token;
+    CHECK_OK(expect(TOK_STR));
+
+    char *type = NULL;
+    char *subtype = NULL;
+    char *ext = NULL;
+    CHECK_OK(preview_type(&type, &subtype, &ext));
+
+    CHECK_OK(expect(TOK_BLK_OPEN));
+
+    Token script = token;
+    CHECK_OK(expect(TOK_STR));
+
+    CHECK_OK(expect(TOK_BLK_CLS));
+
+    add_preview(get_str(name), get_str(script), type, subtype, ext);
+    return STAT_OK;
+}
+
+static int priority(void)
+{
+    print_error("priority is not supported yet");
+    return STAT_ERR;
+}
+
+static int command(void)
+{
+    Token cmd = token;
+    CHECK_OK(expect(TOK_STR));
+
+    char *cmd_str = get_str(cmd);
+    if (strcmp(cmd_str, "preview") == 0)
+        return new_preview();
+    else if (strcmp(cmd_str, "priority") == 0)
+        return priority();
+
+    print_errorf("unknown command: %s", cmd_str);
+    return STAT_ERR;
+}
+
+static int commands(void)
+{
+    accept(TOK_END);
+
+    while (1) {
+        CHECK_NULL(accept(TOK_EOF));
+        CHECK_OK(command());
+        CHECK_OK_NULL(accept(TOK_END));
+    }
+}
+
+static int parse(void)
+{
+    next_token();
+
+    if (commands() == STAT_ERR)
+        return ERR;
+
+    return OK;
+}
+
+int config_load(VectorPreview *prevs, char *filename, char *any_type_)
+{
+    int ret = OK;
+
+    FILE *f = fopen(filename, "r");
+    ERRCHK_GOTO(!f, ret, exit, FUNCFAILED("fopen"), ERRNOS);
+
+    lexer = lexer_init(f);
+    previews = prevs;
+    any_type = any_type_;
+
+    ERRCHK_GOTO_OK(parse(), ret, file);
+
+file:
+    fclose(f);
+
+exit:
+    return ret;
+}
+
+void config_cleanup(void)
+{
+    if (lexer)
+        lexer_free(lexer);
+}

config.h

@@ -0,0 +1,9 @@
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "preview.h"
+
+int config_load(VectorPreview *prevs, char *filename, char *any_type_);
+void config_cleanup(void);
+
+#endif

ctpv.c

@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <magic.h>
+#include <fcntl.h>
 #include <stdlib.h>
 #include <string.h>
 #include <signal.h>
@@ -9,13 +10,14 @@
 
 #include "error.h"
 #include "utils.h"
+#include "config.h"
 #include "server.h"
 #include "preview.h"
 #include "previews.h"
 
 #define ANY_TYPE "*"
 
-static const char any_type[] = ANY_TYPE;
+static char any_type[] = ANY_TYPE;
 
 static magic_t magic;
 
@@ -31,11 +33,16 @@ static struct {
     char *server_id_s;
 } ctpv = { .mode = MODE_PREVIEW };
 
+static VectorPreview *previews;
+
 static void cleanup(void)
 {
     cleanup_previews();
+    config_cleanup();
     if (magic != NULL)
         magic_close(magic);
+    if (previews)
+        vectorPreview_free(previews);
 }
 
 static int init_magic(void)
@@ -49,9 +56,41 @@ static int init_magic(void)
     return OK;
 }
 
-static void init_previews_v(void)
+static int create_dir(char *buf, size_t len)
 {
-    init_previews(previews, LEN(previews));
+    char dir[len];
+    strncpy(dir, buf, LEN(dir) - 1);
+    ERRCHK_RET(mkpath(dir, 0700) == -1, FUNCFAILED("mkpath"), ERRNOS);
+
+    return OK;
+}
+
+static int get_config_file(char *buf, size_t len)
+{
+    ERRCHK_RET_OK(get_config_dir(buf, len, "ctpv/"));
+    ERRCHK_RET_OK(create_dir(buf, len));
+
+    strncat(buf, "config", len - 1);
+
+    if (access(buf, F_OK) != 0)
+        close(creat(buf, 0600));
+
+    return OK;
+}
+
+static int init_previews_v(void)
+{
+    previews = vectorPreview_new(LEN(b_previews));
+    vectorPreview_append_arr(previews, b_previews, LEN(b_previews));
+
+    char config_file[FILENAME_MAX];
+    get_config_file(config_file, LEN(config_file));
+
+    ERRCHK_RET_OK(config_load(previews, config_file, any_type));
+
+    init_previews(previews->buf, previews->len);
+
+    return OK;
 }
 
 static const char *get_mimetype(const char *path)
@@ -133,12 +172,7 @@ static void md5_string(char *buf, size_t len, char *s)
 static int get_cache_file(char *buf, size_t len, char *file)
 {
     ERRCHK_RET_OK(get_cache_dir(buf, len, "ctpv/"));
-
-    {
-        char dir[len];
-        strncpy(dir, buf, LEN(dir) - 1);
-        ERRCHK_RET(mkpath(dir, 0700) == -1, FUNCFAILED("mkpath"), ERRNOS);
-    }
+    ERRCHK_RET_OK(create_dir(buf, len));
 
     char name[64];
     md5_string(name, LEN(name) - 1, file);
@@ -173,7 +207,7 @@ static int preview(int argc, char *argv[])
 
     ERRCHK_RET_OK(init_magic());
 
-    init_previews_v();
+    ERRCHK_RET_OK(init_previews_v());
 
     const char *mimetype;
     ERRCHK_RET(!(mimetype = get_mimetype(f)));
@@ -209,7 +243,7 @@ static int end(void)
 
 static int list(void)
 {
-    init_previews_v();
+    ERRCHK_RET_OK(init_previews_v());
 
     size_t len;
     Preview p, **list = get_previews_list(&len);

lexer.c

@@ -9,15 +9,17 @@
     print_errorf("config parse error:%u:%u " format, (c).line, (c).col \
                  __VA_OPT__(, ) __VA_ARGS__)
 
-#define TOK_TYPE_ALIAS(t) ((Token){ .type = t })
+#define TOK_TYPE(t) ((Token){ .type = t })
 
-#define NULL_TOK TOK_TYPE_ALIAS(TOK_NULL)
-#define EOF_TOK  TOK_TYPE_ALIAS(TOK_EOF)
-#define END_TOK  TOK_TYPE_ALIAS(TOK_END)
-#define ERR_TOK  TOK_TYPE_ALIAS(TOK_ERR)
+#define NULL_TOK TOK_TYPE(TOK_NULL)
+#define EOF_TOK  TOK_TYPE(TOK_EOF)
+#define END_TOK  TOK_TYPE(TOK_END)
+#define ERR_TOK  TOK_TYPE(TOK_ERR)
 
 #define READ_PUNCT(c, t, s) read_punct((c), (t), (s), LEN(s) - 1)
 
+#define EOF_CHAR (-1)
+
 typedef int (*Predicate)(int);
 
 typedef struct {
@@ -38,7 +40,11 @@ struct Lexer {
     VectorChar *text_buf;
 };
 
-static char block_open[] = "{{{", block_close[] = "}}}";
+static char block_open[] = "{{{",
+            block_close[] = "}}}",
+            slash[] = "/",
+            star[] = "*",
+            dot[] = ".";
 
 static void add_token_queue(Lexer *ctx, Token tok)
 {
@@ -74,7 +80,7 @@ static int peekn_char(Lexer *ctx, unsigned int i)
         goto exit;
 
     if (b->eof || (i > 0 && i >= b->len))
-        return -1;
+        return EOF_CHAR;
 
     if (i > 0) {
         assert(i < LEN(b->buf));
@@ -93,7 +99,7 @@ static int peekn_char(Lexer *ctx, unsigned int i)
             PRINTINTERR("fread() failed");
 
         if (b->len == 0)
-            return -1;
+            return EOF_CHAR;
     }
 
 exit:
@@ -217,28 +223,20 @@ static void read_while(Lexer *ctx, Predicate p, int add)
         add_text_buf(ctx, '\0');
 }
 
-static inline Token read_eof(Lexer *ctx)
+static inline Token read_end(Lexer *ctx)
 {
-    char c = peek_char(ctx);
+    Token tok = NULL_TOK;
 
-    if (c >= 0)
-        return NULL_TOK;
+    while (peek_char(ctx) == '\n') {
+        char c = peek_char(ctx);
+        if (c != '\n')
+            break;
 
         next_char(ctx);
-
-    return EOF_TOK;
+        tok = END_TOK;
     }
 
-static inline Token read_newline(Lexer *ctx)
-{
-    char c = peek_char(ctx);
-
-    if (c != '\n')
-        return NULL_TOK;
-
-    next_char(ctx);
-
-    return END_TOK;
+    return tok;
 }
 
 static inline Token read_symbol(Lexer *ctx)
@@ -274,7 +272,7 @@ static Token read_punct(Lexer *ctx, int type, char *s, int n)
 {
     Token tok;
 
-    if (peek_char(ctx) < 0)
+    if (peek_char(ctx) == EOF_CHAR)
         return EOF_TOK;
 
     int ret = cmp_nextn(ctx, n, s);
@@ -337,6 +335,15 @@ static Token read_block(Lexer *ctx)
             return t;           \
     } while (0)
 
+#define ATTEMPT_READ_CHAR(ctx, ch, type) \
+    do {                                 \
+        char c = peek_char(ctx);         \
+        if (c == (ch)) {                 \
+            next_char(ctx);              \
+            return (type);               \
+        }                                \
+    } while (0)
+
 Token lexer_get_token(Lexer *ctx)
 {
     if (!is_empty_token_queue(ctx))
@@ -344,8 +351,12 @@ Token lexer_get_token(Lexer *ctx)
 
     read_while(ctx, isblank, 0);
 
-    ATTEMPT_READ(ctx, read_eof);
-    ATTEMPT_READ(ctx, read_newline);
+    ATTEMPT_READ_CHAR(ctx, EOF_CHAR, EOF_TOK);
+    ATTEMPT_READ_CHAR(ctx, '/', TOK_TYPE(TOK_SLASH));
+    ATTEMPT_READ_CHAR(ctx, '*', TOK_TYPE(TOK_STAR));
+    ATTEMPT_READ_CHAR(ctx, '.', TOK_TYPE(TOK_DOT));
+
+    ATTEMPT_READ(ctx, read_end);
     ATTEMPT_READ(ctx, read_symbol);
     ATTEMPT_READ(ctx, read_digit);
     ATTEMPT_READ(ctx, read_block);
@@ -361,3 +372,34 @@ char *lexer_get_string(Lexer *ctx, Token tok)
 
     return get_text_buf_at(ctx, tok.val.sp);
 }
+
+char *lexer_token_type_str(enum TokenType type)
+{
+    switch (type) {
+    case TOK_NULL:
+        return "<null>";
+    case TOK_EOF:
+        return "<end of file>";
+    case TOK_ERR:
+        return "<TOKEN ERROR>";
+    case TOK_END:
+        return "<end>";
+    case TOK_BLK_OPEN:
+        return block_open;
+    case TOK_BLK_CLS:
+        return block_close;
+    case TOK_SLASH:
+        return slash;
+    case TOK_STAR:
+        return star;
+    case TOK_DOT:
+        return dot;
+    case TOK_INT:
+        return "<integer>";
+    case TOK_STR:
+        return "<string>";
+    }
+
+    PRINTINTERR("unknown type: %d", type);
+    abort();
+}

lexer.h

@@ -7,13 +7,16 @@
 typedef struct Lexer Lexer;
 
 typedef struct {
-    enum {
+    enum TokenType {
         TOK_NULL,
         TOK_EOF,
         TOK_ERR,
         TOK_END,
         TOK_BLK_OPEN,
         TOK_BLK_CLS,
+        TOK_SLASH,
+        TOK_STAR,
+        TOK_DOT,
         TOK_INT,
         TOK_STR,
     } type;
@@ -27,5 +30,6 @@ Lexer *lexer_init(FILE *f);
 void lexer_free(Lexer *ctx);
 Token lexer_get_token(Lexer *ctx);
 char *lexer_get_string(Lexer *ctx, Token tok);
+char *lexer_token_type_str(enum TokenType type);
 
 #endif

preview.c

@@ -11,6 +11,8 @@
 
 #define PREVP_SIZE sizeof(Preview *)
 
+VECTOR_GEN_SOURCE(Preview, Preview)
+
 static struct {
     size_t len;
     Preview **list;

preview.h

@@ -3,12 +3,16 @@
 
 #include <stdlib.h>
 
+#include "vector.h"
+
 typedef struct {
     char *name, *ext, *type, *subtype, *script;
     int priority;
     size_t script_len;
 } Preview;
 
+VECTOR_GEN_HEADER(Preview, Preview)
+
 typedef struct {
     char *f, *w, *h, *x, *y, *id;
     char *cache_file;

previews.h

@@ -13,7 +13,7 @@
 #define PP(e, t, s, n, p) { #n, e, t, s, PNAME(n), p, LEN(PNAME(n)) }
 #define PR(e, t, s, n) PP(e, t, s, n, 0)
 
-Preview previews[] = {
+Preview b_previews[] = {
     PP(NULL,      NULL,             NULL,             wrapper, INT_MAX),
     PR(NULL,      "text",           NULL,             bat),
     PR(NULL,      "text",           NULL,             highlight),

utils.c

@@ -87,22 +87,32 @@ int strlennull(const char *s)
     return s ? strlen(s) : 0;
 }
 
-int get_cache_dir(char *buf, size_t len, char *name)
+static int get_xdg_dir(char *buf, size_t len, char *var, char *var_sub, char *name)
 {
-    char *home, *cache_d, cache_d_buf[FILENAME_MAX];
+    char *home, *dir, dir_buf[FILENAME_MAX];
 
-    if (!(cache_d = getenv("XDG_CACHE_HOME"))) {
+    if (!(dir = getenv(var))) {
         home = getenv("HOME");
         ERRCHK_RET(!home, "HOME env var does not exist");
 
-        snprintf(cache_d_buf, LEN(cache_d_buf)-1, "%s/.cache", home);
-        cache_d = cache_d_buf;
+        snprintf(dir_buf, LEN(dir_buf)-1, "%s/%s", home, var_sub);
+        dir = dir_buf;
     }
 
-    snprintf(buf, len - 1, "%s/%s", cache_d, name);
+    snprintf(buf, len - 1, "%s/%s", dir, name);
     return OK;
 }
 
+int get_cache_dir(char *buf, size_t len, char *name)
+{
+    return get_xdg_dir(buf, len, "XDG_CACHE_HOME", ".cache", name);
+}
+
+int get_config_dir(char *buf, size_t len, char *name)
+{
+    return get_xdg_dir(buf, len, "XDG_CONFIG_HOME", ".config", name);
+}
+
 int mkpath(char* file_path, mode_t mode)
 {
     for (char* p = strchr(file_path + 1, '/'); p; p = strchr(p + 1, '/')) {

utils.h

@@ -32,6 +32,7 @@ int strcmpnull(const char *s1, const char *s2);
 int strlennull(const char *s);
 
 int get_cache_dir(char *buf, size_t len, char *name);
+int get_config_dir(char *buf, size_t len, char *name);
 
 int mkpath(char* file_path, mode_t mode);